Hi Ed, this is an easy one to sort mate....its all in the handle bars...yours is definitely a Model 520081, 4HP Briggs with the elbow and snorkel.
Have a look at the handle design on the machine on the far right; see how the handle turns right up....same as yours....the Cabana (bottom left) turns up a little but not like yours!
Wack on an elbow, snorkel and filter and you're good to go!
