The only complaint I have heard from some Skybolt owners is that the seat position is too upright. I decided, since I hope to spend a lot of time in mine, that I would change the seat position to something I thought wouldbe comfortable. I know my car seat is comfortable (I spend about 3 hours in it each day I go to work) so I decided I would make my Skybolt seats the same rake and angle as my car seats. This required one other slight modification (see the Flight Controls when I get it up). Everyone I had sit in it thought it was comfortable (as comfortable as plywood can be).Only time will tell if this works out. 
(These pictures are a mixture of front and back seats.)
First I measured and cut the tubing to the lengths I needed with angles cut on the ends. I determined the size I wanted by using plywood supported by bricks until I found the angle and size I really wanted..

Next I tack welded the tubes together. 
After that I fitted and tack welded the seat uprights that fit on the back of the seat bottom (this is the front seat). 
Then I supported the front of the seat bottom until I got it at the desired angle. Next was to measure and fit the front supports. (Front seat once again).
Here the front supports have been fitted and tack welded. (Front seat shown).
My next step was to fit the seat back upright and tack weld them on. I then took the seat frame out and welded it.
Here is a picture of the back seat after all fitting has been done and tack welded.
Here is the back seat completely tacked in (front view). You can also see the back supports for the front seat.