I recently purchased a one owner 1975 850 Commando. He's lost
the title and all I have is a 1983 IL license plate. I'm told
that if I try to go through the DMV here that I will either
never get a title or that it will  take forever. Any
suggestions?

Have you checked w/your local DMV? Here in Va. the DMV will do a title search for the last known owner from the VIN# - if it is w/in State they will furnish a new title if your "Bill of Sale" matches their recorded information. If the last owners name and address is not available they will search the VIN# and provide the contact info for you to notify them via registered mail of your intent to title the vehicle. After a 30day waiting period and confirmation of response/no response you can title in your name. As always State Regs. very but check with them. Does Il. have a website?? You may find the answer to your questions there. Good Luck. It's only about half as hard as it sounds. B.