This may be hard to describe. I put a file pic up and will call therm by numbers.
14a being the left lever and 14c the right. I bolt them to the track with a small bolt and nut in the rear hole of 2
cable #20 is then strung across behing the seat frame. I use a hook shape and a spring to hold in place.
this must be just the right length to move the right lever clear of the notch when the left lever is pushed down
The seat is now bolted to the floor with 4 #6 bolts about 1 1/2 long 2 in front and 2 at rear of tracks(I keep these in stock)
the rail itself is bolted to seat frame with 6 #8 bolts and nuts 2 at front 1 at rear on each side .
Most Amphicars that I have run into have had their floor mats damaged by sliding the front seat back. This is caused by a slight angle being formed by the release lever assemblies tilting the slide rails slightly. When they are slid back, they rub against the floor mat and tear it up. The simple fix is to put a 1/8 inch thick strip of aluminum under the slide from the release lever mechanism to the back end of the slide. I bought this material from a local Ace hardware for about $4. The strip is 1.5 inches wide. Cut two pieces to length and drill a hole near one end for the rear bolt to go through. If you like, you can tack glue it to the underside of the track but that's not really necessary. This strip will remove the tilt and save your floor mat. Don't be tempted to use fender washers instead of the strip because there is a lot of weight on those and the washers will concentrate that weight on one spot and can damage the mat. These strips work perfectly and will last forever.