For those folks who are reticent to attack this job (like I was): Did it and it turned out to be surprisingly easy to get at. Removed distributor cap and electrical plug from control pressure regulator. Removed large dia air hose from flame trap and small one from top of manifold, then it was possible to just reach in and pull the trap body (with small hose attached) off the block. Thorough cleaning (or replace if rather - they're cheap. But then so am I) then 5 mins to re-install. Total time: well under 1/2 hr. Piece of cake. Definitely one of those "looks-harder-than-it-actually-is" jobs.

Shame it wasn't blocked up much (could blow through it pretty easily). That probably means the rear seal will have to replaced anyway. Drat.

Who's up for having a dirty AW 70 tranny dropped 2' onto their chest while they're lying on their back on a cold concrete floor? Anyone? No? Not surprising.