Seven courier letters from communists in Germany to Soviet officials in Russia, 1919–20

TASK: take a partial decipherment further: Seven courier letters from communists in Germany to Soviet officials in Russia, 1919–20
This page: https://dbourdeau.github.io/cyphersolver/further/soviet1919.html

You are helping a public research project finish reading historical cipher letters. This one is read in part:
the key works, but some pieces are still open. Your job is to close one or more of the open gaps below.

THE READING
  Write-up:   https://dbourdeau.github.io/cyphersolver/soviet1919.html (read it first: how the text was read, the key, the reading)
  Date:       1919–20
  Outcome:    ciphertext-only break · partial
  Read now:   98.9% of the deciphered cipher tokens give sense (pieces below may be untouched)
  Files:      https://github.com/dbourdeau/cyphersolver/tree/main/targets/soviet1919 (NOTES.md, key, transcription, reading, scripts)

OPEN GAPS (from NOTES.md, "## Remaining gaps")
  1. [illegible: needs a new source] Fortsetzung 2: about 34 letters decrypt but do not read (the opening GALIEIE, OE after "verdächtig", the names PEL…ZIERSKI and RELCW, VILARDOVRRHAFEET before "jetzt frei") - blocker: illegible; the blurred copy is the only witness and there is no contemporary translation of this part
  2. [illegible: needs a new source] Zusatz: one letter of the name O?galski - blocker: illegible; blotted on the copy
  3. [illegible: needs a new source] Fortsetzung 3: the 15 letters of three groups missing from the copy, supplied from the sense and the 1920 translation - blocker: illegible; the groups are not on the copy
  4. [illegible: needs a new source] Fortsetzung 5: "Es geht schön vorwärts" rests on two letters corrected against the copy and matches the 1920 translation - blocker: illegible; the copy is the only witness
  5. [illegible: needs a new source] Schlussmitteilungen: "Auftrag auf Zürich [?]", the copy has ZURUCK and the 1920 translation "Order on Zuruch" - blocker: illegible; the typed copy is the only witness
  6. [needs-physical-access: needs a new source] A human check of the corrected ciphertext against the NARA images beyond the places George Lasry compared by eye - blocker: needs-physical-access; the project's environment cannot reach the NARA images

ALREADY TRIED (from NOTES.md, "## Escalation")
  [x] siblings: the seven parts of the one file read together; no other leaf of M336 roll 75 carries a transposition
  [x] clear-pages: none; the file's English memorandum (frames 0468-0470) is a translation of five parts, used afterwards to check the readings
  [x] known-keys: no earlier key for these indicators is known; none found in the repository or in print on 8 Nov 2026
  [x] print: repository and catalogue searched on 8 Nov 2026 (roll 75, Riga, the indicators, the names); no printed German text known
  [x] key-rebuild: both keys recovered by annealing with a German 4-gram score, then every part re-enciphered and compared letter by letter with the copy

STEPS
0. Set up. If you can run a shell, fork and clone the repository and work inside it:
     git clone https://github.com/dbourdeau/cyphersolver.git
   Then read, in this order: CONTRIBUTING.md (how a contribution is sent and credited); README.md, sections
   "Repository layout" and "Conventions" (how readings are measured and named); targets/soviet1919/NOTES.md in full, and the
   key, transcription and reading files it names; lang/README.md (shared language models).
   Work in targets/soviet1919/. Add your findings to NOTES.md under a dated heading without rewriting what is there, and
   update the "## Remaining gaps" line of every gap you close. Keep WORKLOG.md there: one dated line per step
   (hypothesis, value tried, solver run, crib, control), failures included. Do not edit docs/ (the site is generated).
   If you cannot run a shell, fetch the files from the links above and keep your work in files you send with the issue.
1. Pick a gap. Start with the ones marked "doable now" (open-codes, not-attempted, left-open): the images and the key
   are online, so they need only work. A gap marked "needs a new source" (no-key-material, too-short, illegible,
   needs-physical-access) can be closed only by something new: a key
   or a deciphered sibling found elsewhere, a better image, a printed edition or calendar, a photograph from the archive.
   For those, search for that material first, and say where you looked even when you find nothing.
2. Start from the existing key and transcription in the folder. Do not rebuild the key from scratch, and do not
   re-read parts that are already read unless you find an error in them.
3. For a code group or sign value: list every place the group occurs, show how each reads with the value you propose,
   and say what still does not fit. For a passage: re-read it at the image and give the folio and line. For a missing
   letter or leaf: say where it is held and how it can be reached.
4. Measure again. Apply the key to the whole text, write the reading file, and count the share of cipher tokens that
   give sense (not an estimate). The reading is "complete" only when (1) at least 95% of its cipher tokens give sense;
   (2) no gap is left untried; (3) every letter in it is covered; (4) what stays open is scattered code groups or names,
   or pieces blocked from outside. Otherwise it stays "partial": say which gaps are still open and why.
5. Be honest. Mark every uncertain word with [?], leave unread groups as their numbers or signs, and never fill a gap
   with a plausible guess. A gap retried and still open, with what was ruled out, is worth reporting.

REPORT BACK
With a clone: open a pull request with your changes to targets/soviet1919/. Say in the description which gaps you worked on,
  the share read before and after, and how you want to be credited (name, initials or handle, and a link).
Without one: open an issue: https://github.com/dbourdeau/cyphersolver/issues/new?template=further-reading.yml&title=Further+reading%3A+soviet1919&page=soviet1919.html
  Give the write-up, the gap you worked on (its line in Remaining gaps, or the code group, folio and line), what you
  propose, the evidence (every occurrence, the images or sources), the share read before and after, your step log,
  and the tools and AI model you used.
If you cannot open issues or pull requests, write this report for your human to send. Credit goes to the person who sends it.