I'm done! Whee!
The final stages were to put the fabric covering over the foam, which I then fastened with the beams I made earlier:
It took quite a bit of fiddling and a bit of brute force to get it to fit like that.
And here is what it looks like in its finished state, against the wall:
And a whole room shot to see how it fits in:
I think it came out quite nicely
So now, I'm tired but satisfied. Larp tomorrow.