I’m also very interested in getting updated graphics and rosters into the arcade version of this game. I have a Seattle board with the Boot/Sound and drives for both blitz 99 and 2k gold. I’m in the process of scratch building a 4P control panel for it but I’ve been poking around in the CHD files in between. If anyone has any insight or makes any headway in identifying files/formats or anything like that in the chd please share. I will do the same when/if I discover anything myself.
So far I’ve gotten as far as using chdman to dump an img file, which I had hoped 7zip would extract or windows would mount, but no dice. I went through the resulting img with a hex editor and found plaintext strings of team info, player names, as well as the trivia questions and answers. I have not yet attempted making edits.
I also used the demo of isobuster on the img which revealed a few audio files and some videos but I didn’t want to bite the bullet for $35 for 5 or 6 files. It does however provide the LGA and file size, not sure if someone better with hex editors could use that information to extract the files?
I hope this helps and I hope we can put together a 2019 version!