Hi Jim, and a warm welcome to the forum. It's great to have another Scott Bonnar on board.

My thanks to Rolla also who has given you excellent advice and is spot on...
Your machine is an early 20" machine with an 8 blade reel (that was standard fitment) and the 3 segment rear roller and solid engine deck.
It also has the brass SB ID plate riveted to the deck, which again points to an early machine. My best guess would be 1969.
This machine
may have had a Kirby Lauson (Tecumseh) engine fitted originally and has been retrofitted with the Briggs at a later stage.

With grumpy's help, (our resident Briggs guru), you may be able to get the Briggs running sweetly and as Rolla has said, have the satisfaction of doing it yourself!
I would like to see some more pics with the chain case cover removed, and some close-ups of the sprockets where they are not covered by the chains...particularly the small top sprocket on the primary chain...We can then assess their condition.
It looks like the cylinder reel and consequently the bottom blade (bedknife) could do with a spin-grind and the reel bearings replaced also at that time.

We can help with advice there also.
Once again Jim,

to Outdoorking.
