Boby double used in nude scene?

The original British version had a quick nude scene pretty much at
the beginning of the film after the party scene and it looks like it
was added later as an insert. It is clumsily directed and the girls
body not only looks different from the actress but is really frumpy and
full of cellulite and or rolls of fat....a real turn off! I have never
seen such an ugly nude body double until Meg Tilly's shower scene in psycho 2.

As a note all of the films called Karloff's last picture eg this one, CAULDRON
OF BLOOD,and the four Mexican films had nudity added, In their original
countries releases but cut for the U.S.