Hello and welcome ThomasO,
There are many Allante owners on the AAG Board that might join you when you look at the one you found if they live near you and the car. Let us know where you and the car are located and maybe someone will offer to join you when you check it out. If that does not work out, then try to determine as much vehicle history as you can thru maintence records and history codes.
Also try to determine from the seller if he/she maintained the brakes and cooling system.
Good Luck,
Don