I spied this through a fence and it completely and utterly baffled me. The bottom bar is lugged, It's got cotter pin cranks and what seems to be a drum brake on the back wheel How much is it worth? How old is it? what is it?
No idea. The enclosed chain cases I've seen all have a round chain wheel cover. That cover has a unique shape that will probably ID the bike if you can find another one like it. You'll have to get that bike and take some closeup pics to get a better idea. As for the frame, that center bar may be a locally fabbed up carrier for a child seat or something.