Wasn't it your idea?
I am currently thinking on the lines of three things:
1) As much that can be generated, is generated. So for example, if I could get a list of game name -> ID pairs from HOL I could do a fuzzy name comparison with the other databases. Obviously it will need hand checking, but it should be pretty painless.
2) The site will be dynamic and allow user modification. So if a game is not present, it can be added by anyone. If a link is missing, it can be filled in. Backups of the database will be taken, but by only allowing entering of ID's (number for HOL and CAPS, short mnemonic for AGDB, etc.) we can limit any damage possible.
This is only because resources are not available by single people.
3) When a game is added to any participating project, it could also be submitted to this "game resource link database". Obviously this needs collaboration, but it shouldn't be too much effort. This will avoid problems with keeping in sync.
All this means each project just needs to provide one link - and then users can be lead to all other projects that hold that game. Would be very cool IMHO.
It also assumes the links are not going to change. I know CAPS won't. HOL's? I'll have to ask The Amiga Games Database...
Hosting is not a problem. It will be very low bandwidth, so we can put it on CAPS hosting, or wherever.