Indeed, hacking the number of bio-units worked.  Offsets 14H 15H.  However, take care not to give yourself more than 2500 bio-units...the game freezes at somewhere over 5000 credits when transferring them.  2500 bio-units is 09 C4 in hex, or C4 09 in the savegame file.

I admit it, I'm a cheating bastard.  So, I've been using UltraEdit 32 to track down the offsets in the savegame.
From what I've discovered, RUs are stored at 08h, 09h, 0Ah and credits are at 82h, 83h (least-significant portion first).  I'm able to change the RUs just fine.  However, when I change the credits...while it shows the "correct" number of credits in the game loading screen, when I visit the Melnorme, the number of credits have reset to what I had before I edited the savegame file.  When I re-save the game at that point and look at it again, the values for 82h 83h have indeed been reset to their pre-edit values.

As for me being a cheating bastard, please don't send someone with a  baseball bat to attempt a bugfix on me...