89 ts6m back seat restore

New here. Just bought an 89 ts6m, got a great deal.
Prev owner had been doing some interior restoration work before giving up and selling.
Front seats and the 3 bottoms of the rear are redone, rear back part is in pieces. Cover and foam are acceptable-good to me.

I'm just trying to figure out how this goes back together. I found a lot of threads here on this topic, but they're all so old the images are missing.

Any restoration pics would be great, but if not even any partially removed pics would probably help. Pic without the bottoms would even be helpful.

If no pics, my questions would be...

Does wood go behind the rear back seat? I presume so, prev owner has some pieces cut, but want to be sure.
Is rear back seat stationary (mounted) or removable?

Rear seat is definitely able to be removed, the "back" of the bench is usually all wood, I think I have pictures in under my username of the rebuild I did on mine over ten years ago, jeez cannot believe I have owned this thing that long already. Anyway, I get the boat from the winter slumber here mid-April and can try and provide pictures then if someone else does not beat me to it before then. (cough cough Hunter)

Thanks.
I stared at it for a few hours last night and then searched old for sale listings... I was confused because there is a gap between the back of the rear seat and the sun deck. I was out of pieces so wasn't sure if I was lining something up wrong or missing a piece.

Finally found some pics and looks like there is a flat straight piece that goes in between the two on this model- on some, maybe newer, the sun deck appears to be a bit longer and fills the gap. So, I think I know what I need to do now... Looks like some marine plywood to build a frame for the back bench, then staple the cover around the foam to it. I'll give it a shot myself first, but I don't have much patience for wood, so we'll see how it goes. *Looks* simple enough.

There is a small piece that fits over the top cap piece at the front of the trunk locker. I will have to go back and look at how I built mine but if I recall correctly it was two pieces of plywood that sandwiched a piece of Douglas fir that secured everything in place.

Yes, I found pictures of someone who just used a board to fill the gap as well.

Noticed that underneath this gap there are some holes (4 or 5) in the fiberglass that appear to be made to bolt this piece down.

Another question I have- should this "gap" piece be secured to the back of the rear seat frame so, when the gap piece is bolted down, the rear seat is secured in place as well?
This is the only way I can see to secure the rear bench in place, unless its just meant to sit there unsecured (seems like it will be heavy and tight enough to not have to worry about it moving).

The piece you are talking about is really there to secure the locker lid, the rear seat does not bolt or secure to anything and on my boat it is wedged in there for a tight fit.