1830 cc boxers

I have a spare 1700 carburator boxer engine, that the previous owners took
the carbs of and then left outside, water has gotten in 1 cilinder and it is
not useable anymore without honing/boring and then new pistons. I only
bought this engine for the heads and it was cheap, but now I'm thinking,
there used to be conversions that bore the block to 90 mm with special 90 mm
pistons, and then you have a 1832 cc engine. Supplier of pistons were
Autodelta UK and I believe JE pistons were used by some German tuner. Has
anyone experience with these? How is durability/driveability? Aren't the
cilinder walls getting to thin? Does anyone know a source for 90 mm pistons?
Having pistons custom made is beyond what I want to spent.