I have aquired the above engine when I was given a double pulley for the Greenfield slasher - it was attached to the pulley.

A bit weathered from sitting in a ride-on stuck in a bog in the open - muffler is shot - starter cord broken - bit of corosion here and there - turns by hand - air filter missing. Fuel tank has the remains of something that resembles petrol and there is oil in the sump.
How can I tell if it is worth getting running? Can it be compresssion tested? How can the ignition be checked? - Would there be a market for this size engine if going in good order?
I do have the B&S manuals on disc ( haven't check what's on it for this motor yet)