I'd say it is a prewar Juvenile. Whatever it is, I LIKE it! I don't see it in the Schwinn catalog I have, but it looks like the fork may have been changed. Knowing the serial number would help to nail it down further. Is the headtube drilled for a badge, and if so, what is the spacing? More photos would also help - rear bridge, front of the fork at the shoulders/crown, and the underside of the bottom bracket housing... Is it possible it may be a different brand... Rollfast? The frame looks exactly like a DX to me, but I am not an expert here, just another bike nut with a fair sized group of stuff on hand at home.
The seat post clamp is throwing me a little as I think it is a little different than similar age Schwinn stuff on hand as well. Let me look and see if I have photos of what I believe to be similar aged smaller sized bikes. This is the clamp (integral, not removable) on the '36 model 24" wheel size "B0" - Note it doesn't have the slight bead rolled into the clamp that yours does. My other 24" is a shorter frame where the clamp is through the upper rear stays. Sorry, I don't have any prewar stuff in the 20" size, and only a couple of 24" ones (Great, now I have something else to look for!?!)
My other prewar 24" is a shorter frame where the clamp is through the upper rear stays.
This one:
It looks like the later model postwar Juvenile I am currently working on with the exception of the rear dropouts and the fork. Here are a couple of shots of the '49 model I am in the process of doing. This is a bike that is still undergoing buildup ideas and this is not the planned end result, as the other parts are not in hand yet. Close but not there yet.
This is another 20" prewar, but it was said to be a CWC bike when I did it up some years back, but the seat post clamp looks more like yours.
I have a 20" Prewar Colson, but the seat clamp on it lacks the bead as well.
Hope you get the right answer!! And if you take more photos, I'd love to have another look.
REC
Roland E. Culberson