1968 Barracuda 340 S California car for sale

Well it's easy to see your car is a beauty, and worth a lot of coin. But for a quick sale,those with that kind of money (not me)will want a numbers matching engine and tranny. Whether or not they are in the chassis is not that important. Out, rebuildable, and mothballed is actually probably better..
IIRC 68s may not have the complete VIN stamped, but my 68 stuff (Canadian), does.

So perhaps I should rephrase the question; Are the original engine and transmission available?

Engine is not. I don't know if the trans is original or not.