I don't think its an R3. If you look closely you can see it that it is fitted with a Duplex Pilgrim pump rather than the usual standard model.
The only Matchless catalogued with a Duplex Pilgrim was the 1929 350ohv T/R. This was a variation of the standard TS fitted with an oil feed to the big end for speed and serious competition work. (Factory blurb, not mine) You'll see the owner has also discarded the push rod tubes introduced that year leaving the pushrods out in the open as they were in the previous year when the first OHV 350 Matchless came out.
The timing gear wore horribly on these R & T series. I have a small collection of dead engines including an R, RS, R3, T4 and TS and an equally small pile of horribly worn cams and followers out in my workshop. Regrinding the cams presents no problem but reshaping and regrinding the followers is proving very fiddly.
Matchless knew their lubrication system was inadequate and changed over to a dry sump system in 1930 although you still had to pump grease into the rockers for a few more years before they ran an oil line up there.
So, a very uncommon 1929 350 OHV Matchless T/R.
Cheers,
