[bobbader]

Could be an early 28 starter which takes a totally different switch. If you remove the switch, there should be an insulated copper button about the diameter of a quarter protruding from the starter. It should be flat across its top and the copper should be about 1/8" thick. If, instead, the copper post is much taller than 1/8" on the front side and the top of the button looks like a ski slope (about 5/8" at highest point toward front of the car and sloping down to 1/8" in back) then the car has the earlier starter. reproduction switches for this starter are not made and you need to search for an original switch. I don't know if the newer type switch will even mount on the early starter but, if it does, there will be an immediate and constant electrical contact made which will cause the starter to run continuously once it is hooked up to a power source.
The good part is, if it has the early starter, it is easy enough to swap it for the later version and hope that that cures this and any other starting/running issues the vehicle has. If not, the "$1000 off the top of the price" is a more than viable suggestion.

Good Luck,

Bob Bader