No answers but a couple thoughts...
Al Piemonte Chevrolet is a current dealer w/ similar address as RT. 25 Dundee...could it be the same location but different name?.
http://www.piemontechevy.com/
Also Doane Chevrolet was a Dundee Chevy Dealer operating in the 60's but on Main St..
Dealer Name: Doane Chev
Zone # 11
Dealer # 163
Status: No longer in Business
Address: 10 E. Main St.
City: E. Dundee
State: IL
Any Dealer codes listed in your info?.
Good luck!
~ Pete