Here's a few to start. I have to flip the tub over to unbolt the seat back and remove it then I can flip the side covers up to access the fasteners to get them out. No big deal but its 9 here and I poured a glass of wine after a productive day!

Lower seat cushion. The 1x1x12 at the front combined with gradual increase in thickness of the seat pad raises the front of the seat up so its more comfortable to sit on.

Note direction of 1/2" plywood grain.

I'll measure the diameter and position of the vent holes.

 

Once the seat back is out I'll get you several dimensions.

Yes they are upholstery tacks, larger tacks on the seat back vs the seat bottom

 

I should've given you the dimensions in centimeters

 

Panz, your biggest problem will be finding 1-by that actually measures 1" thick. 5/4" decking may work.

 

Now that would be really cold blooded...would have to use my college math minor skills to convert

Agree. Figuring on starting with a piece of 2 x 2 (or even a 2 x 4) and using my table saw to cut it to size.

 

The side panels. This pic shows the stitching and texture




Basically the side panel bottom isn't too specific. Its below the seat cushion and has to go over the clearance hump for the suspension cross bar.


The backing is cardboard like what you would find in the back of a picture frame. Thick hard paper I guess. The vinyl is stitched to the cardboard but its not attached to the armrest, just the vinyl continues on to the armrest underside and acts like a hinge. You need to be able to flip the side panel up to access the two nuts that holds the armrest to the top edge of the tub.







This measurement is directly under the rear stud. The angle of that panel is just a diagonal down to the forward corner. Again, no real rhyme or reason why they brought it down that far below the side of the seat cushion.

 

Seat back.

 

Another 1" strip of wood but they taper it at the ends.






I'll try to measure how deep the top 1" wood strip is.

 

Springs are wrapped in burlap even against the wood backing. The cotton is very thick and throughout the entire cushion not just the surface behind the vinyl.

 

Thanks Paul for taking the time. Gives me a good basis. The shortest springs I have been able to find are 4 inches. The batting I found matches yours at 1-1/2 inches.