Adopted

Well, it's not the original engine to the Demon, it's a late build '73 model year engine cast April 22, 1974. (Not that it matters).
It doesn't look fresh on the bottom end to me with the slight scuffing on the bottom of the cylinders and the varnish on the pistons, rods, and crank.
The heads look to be 360 heads (because of the gasket size) and would benefit from a good port match/cleanup. If it has 360 heads on it and the pistons are stock, it will have probably 7:1 compression if there isn't been some shaving of the heads and /or block.
I would do a leak down test on it, but it looks okay to me.
It probably won't be a powerhouse though, but it would sound good!