Hi Finbar, and a warm welcome to the forum. I always nice to welcome another Scott Bonnar owner to the forum. grin
Firstly, yes, you have posted your question in the right forum for questions on your engine, and thankyou for posting the pics.
When you are ready to start your restoration can you please post HERE which is the restoration forum for reel type mowers.

Grumpy is our Briggs and Stratton guru here and I'm sure he will chime in here and help you.
I will assist you with any chassis/clutch/ sharpening issues you may have.
Once again Finbar, :welcome: to OutdoorKing.
cheers2

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