Most cases during overhaul of an early engine we do not see exotic materials, You may in some post war big radials, but the Jake, Warner or Continental have nothing fancy to cope with, the cranks and cam rings are usually in good shape, if not they have methods to metalize back to standard and regrind, most we see are over sized cylinders and worn pistons both are getting difficult to find and expensive.
The P&W 985 / 1340 are still factory supported so no big deal there.
designing isn't a big deal in the daily grind of GA