I removed my old seats and made a template of the bottom of the original seat. I wanted to copy the way they were originally mounted.
My wife and I searched at pic'n'pulls in the Fremont, CA wrecking yards, just hoping to find something that was 19" or less wide. That's the magic number to fit into a pinz.
We finally settled on a Kia (don't remember the model) and used an angle grinder to cut off the seats' original mounts. I was able to save the slider track, but it did add an inch to the overall height..
I then fabricated the mount using steel angle, square tubing and 3/16" plate. Angle across the front pinz brackets to support the new seat and bolts welded through the angle to contact the left inside of the left bracket and right inside of the right bracket. This holds the seat securely laterally and the angle sits on the two pinz brackets with the welded bolts under the pinz mounts securing in the forward and upward directions.
A plate was cut to lay over the rear bracket allowing the original pinz wing-bolt to secure the rear. Square tubing and more angle pieces were used to attach the the Kia seat frame.
I can quickly pull the buckets out an reinstall the old military seats since I didn't destroy the pinz mounts.
The only problem that I ran into was having to cantilever the engine side of the seat frames to lift it over the bottom of the engine cover.
My other half really appreciates the seats after our last trip to SoCal and the Calico mogfest (600 miles round trip). Very comfortable.
Just a thought... adding the seats, installing Scott's (E.I) foot-steps and installing a good am/fm CD keeps her happy and makes the driving easier for me too! Oh yes, Scotts' beefy bumper for a bit of forward protection
Now to get back to the camper interior

.....
Thomas E
712Camper (m)
Sonora, CA