Russ.. Right first time. The rear mounting on the frame is the same for both types, just a plain hole. The later frame front mount has the rubber bush and supporting sleeve within the headstock lug, and the later tank has the same slotted front mount as yours plus rubber bushes in the tank rear mounting lugs. This frame type is from 1952/53, and will also have a brazed on lug for a prop stand.
Your early type just requires some nice spacers to prevent strain on the tank mountings. Both tanks interchange with the frame types as regards dimensions of the mounting points, but will require washers and spacers as appropriate to give a secure fitment.
Swarfy.