"This looks a bargain" It could be, depending on what your looking for.
How I see it:
This will be a Lister LR2 (or possibly LD2) which will be anticlockwise rotation, and will be good for about 8 BHP, it will also be variable speed.
Judging by the remains of what is bolted to the engine, it has been cut out of a Wingette 3SH dumper truck.
The missing air filter is concerning as it could be seized up due to water ingress, and the fuel pump inspection door hanging off is not a good sign either.
It is also missing the large 2.1/2 gallon fuel tank.
The PR motors (Newage) 3 speed gearbox is interesting, because if it is any good, these gearboxes are now starting to fetch serious money. Though the perished rubber gaiter around the gearstick could indicate possible water ingress. Easy to check on these g/boxes by removing the top of the gearbox.