Nice find; I'd put the frame around the early-mid 20s. It would have been a 28" wood wheel bicycle originally but somebody later put 26" clincher wheels on it as well as a later 26" Schwinn or Higgins fork. Crank arms appear original, bars likely original, stem may be a few years later. Seat is from late 30s-early 40s.
Despite being cobbled together, it's not like this was cobbled together recently in a collector's hands. It's a bike that looks like it has lived several lives. Revived years later with a few "upgraded" parts here and there when grandpa pulled the ole bike out of the barn so Jimmy could ride it when he comes to visit.
The frame is a bit of a mystery. The exact one just recently showed up on the other bike forum, The Cabe, and a typically surefire bunch, suddenly got quiet and uncertain. To me it resembles a Davis or a Colson built frame. If you can take a picture of the serial under the bottom bracket, I can credit or discredit Davis as a builder, since they had one very unique feature of their serials.