Gave the carb some very sorely needed TLC, put an in-line tap in the fuel line, sharpened the blades and the Corvette is now performing extremely well.
One of the springs associated with the choke crumbled into dust and I was about to remove all the throttle governing system and just have the throttle cable directly control the throttle butterfly but it is running perfectly without that spring.
I find it very satisfying to be able to save abandoned machinery from landfill, even if just temporarily, for minimal cost and a bit of time and effort.
One thing I haven't seen on any of my other B & S motors is the spring loaded tensioner which I presume automatically adjusts the choke when the ambient temperature is low.
The deck is rather rusty. Any ideas what other Victa (or other) decks could easily accept this motor?