Hi David, and welcome to Outdoorking. There are some Scott Bonnar 45 enthusiasts here, and they have a lot of knowledge both about the machines and how to restore them. I suggest you open a thread in Repairs and Maintenance/Questions on Lawnmower Frames/Question on Scott Bonnar Cylinder Mowers. Include some pictures of your machine, and give the long string of numbers stamped on the sheet metal cooling air cowl on the B&S engine. Then tell us about any issues you currently have with the mower. If in the end you are planning a full restoration, you will eventually want a thread in the Restoring and Customising/Reel-Type Mowers forum, but since you will probably be involved in repairing and tuning the mower for a while before you get to the full restoration project, I suggest you start in the repairs area I listed above.
