I am currently working on an 8A with an angle valve motor and Hartzell c/s prop. It had 12lbs of ballast bolted on the tailpost to bring the solo c of g into a reasonable area, no figures to hand.
What we did was remove the ballast as I was not comfortable with it being randomly bolted onto the VS.
The new c of g was in limits for solo, but when I test flew it, the aeroplane was awful. Way nose heavy, poor stalls, full up trim and residual back pressure on final - yeuch.
Now looking at a lead ballast plate in the rear baggage area for solo flight, which my friend normally does, and he is a light guy, so even more issues....