classic motorcycle forum

Like most things there are more survivors than you think but the only local bike I know of is the Shannons bike and I don't know who owns that now. I'm sure someone would be grateful for those remains for spares but I'm no longer the person to ask.
In some ways it wasn't such a hard engine to rebuild. Matchless stuck to the same 69x93 bore and stroke for their 350 engines for near 40 years so a WD G3L piston just dropped in and the same WD G3L conrod was de-engineered backwards to fit. Matchless rarely did clean sheet designs but just steadily beefed parts up to suit later power outputs so for many parts you just have to de beef them and take them back to original. After a while you get to know the early Matchless parts numbering system and can track down many parts used across the range. Sometimes it really pays to specialise in a specific make and know it inside out. Makes life easier.
 

Modaks in Melbourne often have useful small stuff like that, at very reasonable prices.
Think he is mail order only these days.
Worth a try ?

That strange paradox that as the world gets ever-smaller trade and carriage between countries gets more expensive.
{Unless you're China, in which case you can ship and sell anything anywhere for a couple of quid}

Nookys Nuts in the UK is another supplier who specialise in British threads. Nuts are correctly chamfered on one side only. Small bag of mixed BSC nuts is £12 plus postage.

Tread carefully here ?

I don't know about the G2 Bullets, but earlier Enfields had those nuts turned down a shade at one end,
so as to go into the CIRCULAR recess in the timing cover. This means hex nuts won't go.
But they may have changed this arrangement for the Bullets ?

Hitchcocks in the UK would have the real deal.
https://www.hitchcocksmotorcycles.com/partsbook-pages/1444

I think 30 and 31 are what is required (no quantities listed, so cannot be sure.)
They look like just plain cycle thread 1/4" nuts.

Luke at Britcycle.com.au had them NOS at $1 each, cad ? plated.
You'd have to chase the washers - stainless ?

Interesting sounding project. ?
Can we see it when done