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.

Attachments
IMG_20190828_160456-1000x563.jpg (134.94 KB, 97 downloads)
IMG_20190828_195552-1000x563.jpg (66.53 KB, 97 downloads)
IMG_20190828_160559-1000x563.jpg (129.57 KB, 97 downloads)
IMG_20190828_160612-1000x563.jpg (138.13 KB, 97 downloads)
IMG_20190828_160543-1000x563.jpg (81 KB, 98 downloads)
IMG_20190828_161910-1000x563.jpg (144.31 KB, 98 downloads)

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!