RE: 3 Cyl 049 radial
These tiny radials tend to pup up now and then, below is a picture of the g-mark with individual crankcase spaces and a gear system (no compressor needed). There is also a video of one running [link=http://www.youtube.com/watch?v=d28vqW8pJlQ]HERE[/link].
I've also attached a pdf file (not sure if that works) of a compressor driven engine from germany.