If you're just looking at a reimplementation of the old game, you could talk to
Krome Studios, the folks who are doing the remastered Bard's Tale Trilogy. Part of what they've been doing for the project is going through the disassembled code of multiple versions of the old games to see how they were different between the different computers and distilling everything down to a single modern version.
Something they found recently: in one of the games the monsters should have been able to cast a certain spell, but in many (all?) versions it never worked properly and the code just cast a different spell instead. Those monsters should be much deadlier in the remaster.