Here it is as installed. The sides are "coped" to fit the window; available materials worked out to slightly less than full width of the window frame; this is actually a good thing, as you'll see. (That's a Device on it, a partially-restored 5-meter radiotelephone transceiver, a sort of 1930s cellphone). The tall bookshelves are what the room will eventually be lined with. The shorter ones are temporary and about twenty years old.
The reverse angle shows the stenciling (all hand-cut by yours truly. Yes, it does say "Airship Parts, and why not?) and "decal," which is an iron-on inkjet printer transfer for cloth, a trick that worked better than I expected. If it seems a little familiar, that's because it's the old Railway Express (the FedEx and UPS of their day) logo.In that photo and the next, you can see how it just fits in the inside width of the window frame.
With the cushion in place -- a folded comforter -- it has enormous cat-magnetism. The width works out just right for a Full size comforter.
Construction detals: It's pretty much a box sitting on another box; the base is just (nominal) 2" x 8" pine from the scrap-wood pile, butt-jointed; glue and big deck screws hold it together. It clears the baseboard at the back.More scrap, 2" x 6", extends the base horizontally at front and back, trimmed flush with the base on the inside after assembly. This provides a toe-kick overhang at the front and baseboard clearance at the back.
The upper part is a three-sided box, open at the back, held to the 2" x 6"s with more deck screws (hidden behind the oak trim) and held to the sides by shallow "Kreg" screws. The open back is framed with 2" x 4" wood for strength, with vertical posts and a front-to-back 2" x 4" at the center and another 2" x 4" centered under the hinges to support the seat (you don't rely on the hinges!).
It is heavy, but not as heavy as you'd think. The hinged seat feels solid when you sit or relax on it. Worked out pretty well for something I mostly made up as I went along. I had dimensions in mind but that was about all.
