Next to Harley, (you can get enough repop parts to build a new '36 Knucklehead from scratch) Triumph parts are the most available in the world.
They didn't have the computer design systems they have now, so motorcycle engines made in those days with cases that split vertically are almost sure to leak at least a little. Note that, through the early 60's, the HD spec for oil consumption was 250 miles or better to a quart. When calculating by sliderule, it just wasn't possible to fully compensate for heat distribution and expansion. That's why Japan.inc started splitting cases horizontally even though that greatly weakens bearing support and BMW's (Maybe Sunbeam too, can't remember) added a sump at the bottom of the engine.


Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python