What Airplane is this ? Small nitro motor

Wen-Mac Corsair. It looks like the Wen-Mac MK II engine. Extremely fragile so use caution, don't force it over. Take it out, soak it, heat it . I see what appears to be rust and that's a bit concerning. Hopefully that didn't migrate into the cylinder. Somehow the needle valves always go missing on these and they're not exactly easy to come by. This is a very anemic engine. It appears to have the Roto-Start spring starter. Never wind these up, just turn it back a 1/2 turn and let it go. Taking the spring assembly apart isn't exactly a simple task. I would just free it with oil and heat.