Quote Originally Posted by mlochala View Post
Looks very similar to a brake master cylinder and caliper.

Porsche 914 Brake Caliper
https://ic.carid.com/cardone/replace...19-434-2_1.jpg

The smaller piece looks like a master cylinder that has been cast but not yet drilled, bored, and tapped. Was your friend into building cars or car components?
That introduces another possibility; could those be cores, elements of sand castings to produce cavities?