Thanks for that. So, are we sure that the first SB45s had Briggs engines and the Kirby Lausons came later? Can we find out when this happened, perhaps from the last mowers to have Briggs engines (since the Kirby Lausons are not so easy to date)?
A small point: from what we have traced in another thread, the 60102 appears to have had the small flat fuel tank used on the vertical engines, because it had no fuel pump. After a while SB seems to have changed to the 60202 (with Pulsa-Jet, which has a fuel pump) and a large deep tank mounted under the carburetor. Do we know when that happened?
