Dan, I must have taken a zillion photos of the build, but for some reason cant seem to find any or I didn't take any of the seat mount.
So I will try to explain what I did, if it doesn't make sense let me know, everyone else does, except my Mrs, she ignores me when I don't make sense.
My passenger seat is fixed in place and isn't adjustable.
For the pass side on the car floor I have two- 1/2 by 1 inch 16ga tubing running sideways under the seats from the tunnel to the outside.
These are welded to the floor.
Then 90 degrees to those tubes I have two- 1x1 square tube, same stuff as the frame, these tubes sit on top the welded 1/2x1 inch.
At the front of the 1x1 tubes I have a piece of 1/8 inch steel plate welded, the front tube is cut at an angle so the 1/8 inch steel plate matches the front angle of the kirkey seat.
The 1/8 inch steel plate has a hole drilled to match a hole I drilled in the front portion of the Kirkey seat.
The back portion is much the same using a spacer between the 1x1 tube and rear seat location.
The 1x1 square tube is drilled near the ends and bolted through the 1/2x1 inch tube and floor.
The driver side is adjustable, it has the same 1/2x1 inch 16ga tube welded to the floor as well.
To this I bolted some adjustable seat runners I got from Speedway, the cheap ones.
The front part of the runner has a bolt installed from inside the track with the threads sticking upward.
I then welded a nut inside a piece of 3/4 inch tubing, the tubing is around 3 inches long.
I then threaded the tube onto the bolt sticking up on the adj glide.
The other end of the tube has a flat piece of steel that is welded to the 3/4 inch tube, the tube is angled to match the seat , then I drilled two holes in the steel plate, plus two holes to match in the front portion of the kirkey seat.
The back portion was done using spacers and the hole drilled in the kirkey seat to match the stud in the rear portion of the glide.
The seat angles just depend on the length of front tube on the adjustable one and the length of 1/8 inch steel flat bar on the pass side.
I used button head bolts on the inside of the seat with 1.5 inch steel fender washers and with the bolts through the floor pan I just cut some 1-1/2 by 2 inch 1/8 steel plate to go between the floor and nut rounding off the corners.
The seat padding is plenty thick enough, so I have never felt any of the bolts underneath.
There are setups for side seat mounts, which are a nice way to go if you have the room, I didn't, so my mounts are under the seats.
I am sure there are lots of other ways, some worse some better.
Hopefully this heads you off in the right direction which ever way you do it.
It was pretty straight forward and simple, if my explanation isn't the same ask away...
Al