cylinder head identification

Hi Forum,
I have stumbled onto a set of aircraft cylinder heads, that were carefully tucked away in the loft of an old barn we were cleaning out. They are in great condition, but I have no idea what they fit or how old they are. There is no manufacture name I can locate, but a bunch of numbers stamped in castings. They are marked right and left, which leads me to believe they are from a two cyclinder. Could I get some advice on the best way to identify what they are?

Plenty of flat 4 and 6's use individual cylinder heads also.
Posted pictures on here might be recogniized by someone.