Hi Jim.
The Corals are really great drivers, I have 3 pair and they are all very nice.
I think $650 is a bit expensive, $300-$400 would be a better price, but maybe they are getting more and more rare.
These are the T/S parametres for my Corals.
As you can see they vary quite a lot vith age, so it´s hard to say exatly what T/S your pair has without measuring them.
The link below is to a great website with everything you need to make a cabinet.
I would use them in a backloaded horn, but they sound good in a BR too.
Whatever you choose, I don´t think you will be dissapointed.
Regards
Kim