Glen...not to step on your midstates "speak with Bob " query, but some info on state of michigan license and title:
1. any questions re Mich state law could be directed to their Secy of State offices at :
http://www.michigan.gov/sos/
2. I would guess that to title the car in Michigan, the prior owner would have to pay a 6% sales tax on the value of what he had accumulated in parts/body/frame etc...and in fact titleing it before it is completed might not be possible.
3. to license the car he would have had to have a completed vehicle and pass a state inspection ( local police authorities do it ) in which case , again, state tax would have to be paid. the licensing process also would include title application.
there used to be ONE Person in Springfield Illinois who handled Cobra type registrations, especially as it related to whether or not they needed to pass , or were exempt , from Emission inspections for those areas of the state that still impose emission laws.
if your contact who gave you the advice you posted is not from Springfield, ie, it was your local SOS office, you might want to double check the info you got from the Illinois State SOS office at :
http://www.sos.state.il.us/contact/contact.html
just some thoughts...I tried to sell a Mich registered SPF one time to a friend in an emission area of Chi suburbs and found the engine was not exempt from emission laws and the deal fell thru...however, in this process the prospective buyer and myself found the Springfield SOS 'Cobra replica' expert to be easily reachable by phone and a wealth of info that was not always the same as the buyer had learned from his local SOS office in the burbs.
Good luck. Bill.