Hi Christophe
I think you could equally go two ways with this, either using the civilian frame to build up a 1946-style machine or the W/NG frame and forks to build a 'civilianised' W/NG (there were plenty of those) perhaps with the option of returning it to military specification at some time if ...

If it follows the same pattern as the GB box that spring will be fitted to the inside of the cover plate, probably with the ends being kept sprung apart so that it fits over the selector plate. As the plate moves up and down it would then engage with one end of the spring in each direction.
(Not ...

That ebay stand (assuming it's item no. 116637819977 ) looks quite good BUT do I see re-welding on the front of the feet?
Also the feet look a little 'flattened' to me so they might not be in the best of nick (they often wear very thin against the ground).

That rust isn't a problem (buy some citric ...

Good examples of these are extremely hard to find - knackered ones might be slightly easier to come across but you've got one of those already!
I don't think that's a bad price at Drags for something that's as rare as hens teeth and available off the shelf.

You're right about the pins, and the ...

Vertical travel on piston. Ariel only ever specified 1/2 BTDC as standard but 5/8 BTDC for high compression. The latter seemed to include everything from 'fast touring' high compression to the out-and-out scrambler.
As Simes says most folk probably just get a feel for which settings work best.

SG

I think Nev's comment was about the fins being more style than function, not the clamps themselves.

SG

A word about the rocker-box gaskets - if/when you tighten down the rocker box and the gasket sinks slightly you lose twice the amount of 'sink' in the tappet clearance (and with an iron head there's not a lot of clearance to play with!)

SG

Just get maybe 1/2 dozen each 1/4 BSF and 5/16 BSF, maybe 1" set screws (threaded all the way down, can be cut shorter if necessary) +nuts.
It's the nuts and bolts holding the tinware on that are most likely to fall out unexpectedly and these will replace most of them.
(Original threads would be ...

Semi-fluid grease, see also Drags
https://draganfly.co.uk/shop/83795/gear ... 11/#OI-GRB

SG

Straight 50 is fine for the engine (and chaincase) - I wouldn't use anything else in a single (except drop to 40-grade in winter). Others will differ but as you're using that for the Matchless already why complicate matters with anything different?

Oil levers as per the Matchless (ie to level ...