Front end alignment at home

Actually Rob that is not true. If you can measure CAMBER then you can measure/ calculate caster. My old Ammco caster/ camber gauge measures camber, and caster is computed from that by what amounts to a rotary slide rule on the instrument.

You measure camber with the wheels turned one way, 20* in, then measure camber again with wheels turned 20* out. You figure the DIFFERENCE in that reading and multiply X 1.5 That answer is your caster

But you still have to have the tool, right? That was my point. We had an OLD Bear mirror machine at the KMart Auto Center where I met Kitty years ago. It had the very caster/camber gauge you describe. It was archaic, but I liked it because it worked.