Hi Mr Davis, I pulled Frankenmower out and after some unnecessary dismantling of the engine cover and petrol tank, discovered the number on the RH side. I had thought the number would be on the carby side, based on a low arch I examined earlier. The number appears, upon careful examination with a workshop light, to be as follows: 119-770-778. Some pics of the machine including the rebuilt carby and kill button I fitted using a zip tie! Engine sounds energetic. Yes I know, the snorkel sticks out. It needs the proper snorkel.
Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!