I think this is a fabulous idea. Would a stickied post in the Trading Post fulfill this need? Members can reply to the post saying which numbers to look for, and the Trading Post moderators can compile those replies into a list in the first post something like this:
[spreadsheet]Number°Requested By
0161976°Fenian
0251968°CDNmooha
1061947°CDNmooha
1061976°Fenian
1161975°CDNmooha
1171925°eyevet
1251953°eyevet
1281993°eyevet
1341952°eyevet
2811993°eyevet
4131952°eyevet
4740734°Fenian
5121953°eyevet
5441944°Fenian
6111975°CDNmooha
6160128°eyevet
6204672°eyevet
7111925°eyevet
7292004°Fenian
8299444°eyevet
[/spreadsheet]
This would serve as a community-wide wanted list for specific serial numbers.
If you like the idea, now is the time to massage it into the perfect solution that suits people the best.