Isn't that a Dooling decal on the cowling? That would make it a .61 or a .29, the only sizes they made, and it's too big to be a .29.
The airplane actually looks a little large for that class from that era. My dad had a lot of success with one about that size, but most were much smaller. Also, most of the designs from that era had already dispensed with the rudder.
I can't tell from the pic if that's a cast pan or not. Those were pretty new then, mostly custom made. The step in between maple crutches and engine bearers and pans was an aluminum or steel engine mount that bolted to the crutch. I have one of those in my collection.
It seems to have a plug-in type dolly, which had fallen out of favor by 1949. I think the cradle type dolly was most common then and some early versions of the mouse trap arrangement were coming along, too.
So, my guess is that the photo is from a couple of years before 1949, or the builder has done a nice job on an older design.
I like the way he's put a little hatch over the glow plug.......attention to every detail!