With the wheels in motion, we can start to look at the brakes. The front is still on the bike, but the back is off and apart:
There is nothing particularly horrendous to report at first sight. The linings are nice and thick, there is only a moderate amount of greas and gunge around and everything operates as it should.
But what is this? This little bodge is revealed when the cam is removed. The brake cam shaft measures 1/2" OD and is unworn. The hole in the brake back plate measures 5/8" ID and is unworn, so what is going on? I would have guessed that this little 'sleeve' was doing service to fill up a worn hole, but no. A session with the Ariel parts book and Drags 'List 15' leaves me none the wiser.
However, a chat with Mick at Drags reveals all. Having found me my missing adjuster, Mick goes to look at their stock of brake plates and finds that one of them has a bush pressed into this hole - part of the brake plate, hence no separate part number or identification in the parts book.
So now I have some 5/8" x 16 SWG seamless tube on the way from eBay..