Steelonsteel,
Block casting# 3769717 decodes as a 1959-62 "261", rated at 135 HP. Definitely a US Chevy engine I do believe.
Can't offer much for the serial# as the picture doesn't show the whole pad, which may need a bit more cleanup to fully expose all the the stamped digits. Would also help if you can locate and report the "date" casting info on the side of the block directly above where the starter mounts. That and the full serial number info will help better pinpoint your engine info.
The head casting# 3836848 decodes as a 1956-62 "235" with 4 bolt rocker cover and large diameter temp sending unit hole in the head.
PCV setup (for the most part) is correct for the "261". I think the vented cap on valve cover is a transplant from something much later and the large vacuum port manifold and lines definitely make this a "Big Bolt" contender.
Nice to see you have such an enthusiastic helper.
Dan
