Vintage Bike

We picked up this bike last weekend and need help identifying the brand and approximate age. The chain guard says Silver Flier which would be a Western Auo bike, but the chain guard and the chrome fenders that were on it don't seem to fit correctly so I thing they were a retrofit (along with the bad black paint job). Also, the curvature of the front frame bar doesn't look like most of the pictures that I could find of Western Fliers. I found a picture of a 60's AMF Roadmaster that had a very similar tank light and the frame curvature looked more like this one. The only label we have been able to find so far is the decal with the black R on a gold background. One post that I read said that Western Flier put the serial numbers on the crank housing. We couldn't find any numbers there but did find serial numbers on the tail of the frame next to the real axle slot.