Afraid this needs a bit of history. The 28 inch wheel and 24 inch frame bike with angles around 67 was originally built for the rough roads of the Edwardian period, and would have all solid ends brazed in, but the seat stays oddly were bolted on. The cranked stays were to provide clearance for 1 3/4 inch tyres and imperfect wheels. By the 20s the solid ends were replaced by just pressing the ends of the tubes (called trapped ends). the rear stays on these were incredibly weak.
This rather stupid design was maintained but diminishing in the 1930s. By the late 30s these were relegated to the end of the catalogues, back with the juneviles and carrier bikes. They were built with 12 inch bracket height and far too large for many users.
The method of mounting was to stand on the left of the bike, place left foot on the pedal and push off with the other foot and lift the right leg over the saddle when going fast enough.
This was obviously not suitable for the increasing traffic conditions and regulations by the late 30s. So bikes were made with fully brazed stays and steeper angles, 10 to 10.5 inch bracket height, 26 inch wheels and the riders could put a foot down instead of dismounting.
Rod brakes were often the choice of commuters. The average bike had absolutely no maintenance and rod brakes would still just about function, where cable brakes actually needed a little oil on the cable ends about every 6 months.
Post war 28 inch wheel bike were exported in large quantities but were very rarely sold on the home UK market.
Keith