File triggers BugSplat immediately on File > Open in SketchUp 2021 Desktop
File was stored in a Google Drive-synced folder (likely cause: sync process interrupted a write)
No autosave (.skb) or Windows Previous Versions available
A Drive "version history" copy exists but is significantly outdated (~30% of the work)

Binary diagnostics (done via Python, byte-level inspection):

File size: 189,946,064 bytes (~181 MB)
Header is fully intact and valid: identifies correctly as "SketchUp Model", version {21.0.339}
File is NOT a zip container (confirmed — this format doesn't use zip)
No truncation: high-entropy (compressed-looking) data continues consistently all the way to the last byte — this does not look like a file that was cut off mid-save
Exactly 3 zero-byte runs found, each 10,479 bytes long, total ~31KB out of 181MB (~0.016% of the file):

Offset 52,117,304 (27.44% into the file)
Offset 54,164,814 (28.52% into the file)
Offset 56,330,073 (29.66% into the file)

Notably, the 200 bytes immediately preceding each of the three zero-runs are byte-for-byte identical across all three locations, and the data immediately following each zero-run also starts identically. This doesn't look like random corruption — it looks like a repeated/duplicated write pattern, possibly from the Drive sync process re-writing the same buffer multiple times with gaps left zeroed.

Given how small and localized the damage is relative to the file size, I'm hoping this is recoverable. I don't have tooling to parse the internal SKP structure myself. Would really appreciate help from anyone who's dealt with this kind of corruption before.
File (181MB) available here: https://drive.google.com/file/d/10b83OPyXvXJR0ye1WnDF7evvtJPkdKuE/view?usp=sharing
Thanks in advance — happy to provide any additional diagnostic info needed.