@a71f39de I suppose that would explain why bit 7 is so hard to reduce because it has more randomness. Would be great to understand the serial number format to assign proper new serial numbers to all of the #AppleLisaClone being built. 

Good news is the PROM on the I/O board for the floppy should be the same for all of the clones. 

http://www.bitsavers.org/bits/Apple/Lisa/firmware/341-8003-A_f95908934da6460a67abc26c2f0d1553.BIN