I have the original tape, in two versions, and the cover has no trace of Comptiq whatsoever.
My covers do not contain any logo of Erbe, because it was released in the Netherlands and not in Spain. Actually, the cover is exactly the one you can find at Release 1 in Generation MSX, it's the right one. (The left one is the ERBE version.) Those covers clearly have "MSX 64K" on them, just like the covers I have here.
I think the MSX version was probably programmed by Comptiq (I haven't run the cassette to confirm), but the box contains the logos of US Gold, Sydney, Sierra On-line and also the producer, ERBE or Eaglesoft (for one of my covers).
So, in the Netherlands there were at least two releases, which I both have:
- one by US Gold itself (Release 1), see this cover:
http://www.generation-msx.nl/compiled/msxdb/thumbs/covers/B.C.II._Grogs_Revenge_-US_Gold-.jpg
- one by Eaglesoft (Release 3), which also contains the US Gold logo; I'll upload a cover for it after my holidays
and in Spain there was also one by ERBE (Release 2).
The original game (on some non-MSX platform) was probably created by Sydney or Sierra On-Line, or both.
