There are no credentials other than seller's comment about the 1951 Convertible. Some were made from club coupes by owners after the fact. Need to see the firewall tag for codes that would establish this is a factory special build.
Otherwise, buyers should be aware that there could be structural issues with the car because it's missing the steel top that helped keep body integrity. You do need a cross-member added to the frame to compensate (the extra chassis steel gives more points on the lower body for mounting points to keep the remains of the shell viable).
