Yes - maybe the North Ken Middle Row (X) 187s were the Leyland ones; the 140s were all RTs [all from harrow Weald garage, despite the length of the route?], which made the engine sound identification useful on the stretch where they were the (only) two routes - ie from Eastcote Lane in South Harrow up to the top of Petts Hill where the fire station is. I lived in a turning off that stretch for almost all of my school days. (I guess there were 187s from Alperton too - but weren't they Leylands as well?)
A historical question about the buses around there - since there might be someone here who'd know. A lot of the housing west of the A312, between South Harrow and Harrow (ie roads off Roxeth Green Ave, and around Shaftesbury Circus) were "green fields" developments in the 1930s. I had relatives there, and we always had to walk there from South Harrow to visit them, because the buses all went on the main road to Harrow-on-the-Hill station, even though there was quite a stretch where almost no-one ever got on and off. Then suddenly someone had the bright idea of looping the bus routes between S Harrow and H/H (the 140, 114 and 158 at that stage) round via Shaftesbury Ave, Porlock Ave, Lascelles Ave - ie where lots of people actually lived. And very popular it was too (with the old folks especially, who wondered why it hadn't happened a lot sooner). Question - when was that routing change made? I'm guessing early-mid '60s?
I caught some of the heritage outing today (despite engineering work on the underground messing up my plans). And I was especially pleased that the old buses weren't "just" RMs (which are often seen as our great heritage these days), but there was a load of RTs running. So we had the real 1950s and 1960s 140s - many thanks to whoever managed to get a good batch of RTs together for the day. The rear upstairs seats on the RTs have memories for me as pleasant as the rear upstairs seats on the RMs! (Question - I know that RMs started coming in during the '60s, but am I right that they didn't take over from RTs on suburban routes like the 140 until well through the '70s? And indeed, I guess the RMs out there were themselves superseded by OMO buses after not very long?)
The southbound RT I was on from H/H today seemed to struggle slightly going up Petts Hill from Northolt Park station. Mind you, I remember when they were still new-ish buses, going up that hill to school one winter morning with a lot of snow around (late '50s ish), and the conductor pleading with people not to want to get off at the bus stop halfway up that hill if the bus was ever going to get moving again...
Another RT I saw heading south (out of service) late this afternoon, when I was walking back to South Harrow, was making some very unhappy-sound clunking noises, and moving quite slowly. Did all the RTs survive the day OK?!