Well Ray, just take this one, bought off eBay for $1400 and which needed a $250 bridge and tailpiece assembly to be complete, and subtract the cost of repair labor and parts to make the May 73 identical to the otherwise minty hardware condition of this refin 72:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=015&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=250095995080&rd=1&rd=1
This 72 is a refin, but in-person it turned out to be good enough to leave as-is.
For your carcass, you will need to be able to buy the two pickup assemblies ($250 new for a 4003 set from RIC), four period tuners and bushings (at least $250 used, sealed non-wavy Grovers), and a quality refin and repair of the holes in the headstock for $370 or less (which I think is impossible to get done for only $370) and $30 for a good set of strings. All that would have to total $900 (the difference between the $1650 paid for a complete 72 and the $750 this guy wants for a May 73 carcass).
Since I think the refin will cost more like $870 minimum, maybe $1000 from one of our master luthiers here on the Forum, and the above budget only allows $370, you would need to be able to buy the carcass for no more than $250, not the $750 the guy wants, to make it feasible.
Based on recent sales of parted-out 4001 on eBay, this guy could get $200 alone for an all-original electronics and pickguard assembly, I doubt it is worth it to either you or him at anything more than $250 for the carcass. Besides, the 72 fretboard would have been valued a bit higher than the May 73 fretboard anyway, so even $250 would be too much for you to pay for the carcass.
