Here's a few shots from the Neomega site:
Vector Scale Resin Model Engines
Sergey's work is about the best there is. All his rotary engines are true to scale - so much so that getting them in kit cowlings is impossible without sacrificing cylinder head detail or
drastic thnning of the cowling - I have done both on the Eduard Sopwith Pup.
These engines aren't cheap, but you really do get what you pay for in this case!
I haven't seen the Pavla one, so can't comment.