I just purchased a house that was sold by the estate of a 93 year old lady that passed away. I found many treasures that were left behind gathering layers of dust in the basement. I could list so many things that I have spent hours on-line trying to find. However, I am very interested in a 10 inch turquoise flower pot with a cursive R U.S.A and 51-10. The leg of the R is long and extends down and out. It might have had a curl at the end but it's hard to tell. The dry foot unglazed area appears to be a reddish brown and it appears that red clay is showing through the glaze.