Manx Norton Engine. 500cc. Late Short Stroke. Cooper 500

Genuine Norton 500cc Short stroke engine. Late type. two broken fins. with a spare barrell.
The engine turns over smoothly and looks as if it was removed to repair the broken fins and work was suspended. The spare barrell has a small piece of the bottom fin missing and the next fin up is slightly bent. but both are fairly straightforward repairs.
The numbers are clear. its a 1959 engine. The type which has the straight cam tower.
Also has the letters VM stamped on the front case [not casting marks]. All magnesium. Nice original engine. Just have some history somewhere. Ideal if you've got a rolling chassis.