Hi Brett, and a warm welcome to the forum. It's great to have another Scott Bonnar owner on board. grin
Here's some info:

The Model 33 Mark 1 Scotty was first introduced in 1960 and is a 16" machine with a Villiers 98cc, Mark 3 'Midget'...2 Stroke engine and all chain driven and a segmented wooden front roller. wink

The Model 33 Mark 2 (also 16") was fitted with a Kirby Tecumseh HK25, 2.5Hp... 4 Stroke engine and was belt and chain driven and the metal front roller and alloy end caps.
Which one is yours?

Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin