Hi all.  I wanted to share this spreadsheet I've had compiled for a bit in case no one's got something already out there (I couldn't find anything).  There are two tabs, one with offsets on a headered ROM and a tab for a ROM without a header.  I've got both Decimal and Hex offsets here as well just in case.  Thought this might help anyone wanting a quick way to see what free space is in a normal unmodified ROM.  Feel free to post this elsewhere but please give credit.  : 

http://jce3000gt.c