PBR Streetgang

I'd like to buy a prewar bicycle frameset in the motorbike style (like an Elgin Motorbike from the 1920s) for a project. Liking a bike to be somewhat light, does anyone know of a reasonably lightweight frame from that era. I'd like to exclude high end, very rare, or custom items. And believe me, I know we are dealing with heavy frames here. I'm just looking for a frame that might have been a pound or two lighter than the run of the mill.

Thanks in advance!