Just found this thread (normally only read the non-sports side), but since I was mentioned a couple of times, thought I would offer some information.
Marhoefer has been mentioned many times in this thread. Here is my known checklist:
http://www.thecarburetorshop.com/Mar..._checklist.htm
Here is another link to my website listing a few automobile and racing sets:
http://www.thecarburetorshop.com/Automobilecards.htm
This list NEEDS a significant amount of updating, but as one grows older, one realizes that time is one's most valuable asset!
Jon.