> How can I get around this? Can I just use an empty file with the proper ROM image > name that MAME is looking for? Or some other method?
Correct.
It can only be done via command line where a part of a romset can have rom piece with the same label but different hash values. MAME should tell you that you have a non-matching hash, but allow you to continue loading the emulation. Just launch from command-line as noted in documents.