RRS Corbeau Seats
I put Corbeau seats in my '68 Barracuda convertible using their mounts. I did have to modify the brackets slightly to lean them back a bit more, but it was quick and easy. I love them. Picture is from before I had the interior done professionally.
Note to self, don't put leather seats in a convertible. While they held up for many years, the leather began to shrink. I have since them recovered in German Marine Grade vinyl.