My RGS had the flat stays on the mid front mudguard position from new and over the years I've seen other RGSs that had the same.
When making tubular stays it's important they should have a close fiting smaller tube inserted in the ends before flattening, that way the outer tube isn't too weakened. Also, the flattened end should not form a straight line from side to side but have a curved arc shape. That way, a straight fracture line is avoided. It's worth making a jig to do this and a jig can also allow the tube to be bent symmetrically (top and botton have equal amounts of pinch) or asymmetric, when the flattened lug is on the bottom. (I hope that's reasonably clear). I made my jig
over30 years ago and it's earned its keep. Flattening these tubes within tubes needs serious force. The jig has exchangeable forming plates with different radii for the arc. I used to rest the jig on a 300lb anvil, put a2 inch long piece of 30mm brass rod on it, and show it the way with a sledge hammer. Now I use a hydraulic press. BSA used to drill a small hole near one flattened end of their stays so that after plating, any trapped plating solution could be shaken out. They even used to chamfer those tiny holes :-) I hope that helps, Jon