This particular dropout is 6mm thick. Later in 1951 it changed to 7mm thick with a 4mm screw at and stop at 7 o'clock. In 1952 it changed again to 7mm thick with a 3mm screw.
huh, I have a bike that might be a year or two older than I thought. Of course dropouts did not really have model years back then. Mine is 4mm and 7'. Mine has been sitting longer than any of your projects. One day in Retirement.
I'm sure it wears the wrong color, but not to far from McLaren Orange, so should be fast.
just don't paint it Silver, there are too many silver bikes now.
looks Long, back during the era where generous wheelbase was a feature.