classic motorcycle forum

Looks like someone's scratch built rectifier, good effort but easier nowadays to to buy a standard bridge rectifier. 

It may be me and the angle it's pictured but the two wire terminals look like they are under the screw head rather than between the insulating washer and contact carrier.

Yes shim stock, .1mm thick. Here's before and after pics, I didn't  want to repaint the tank because I'd lose that originality so have done little cosmetically on any of the bike.

I too worried about electrolytic action between brass and alloy so have ordered stainless shim (I never thought about a drinks can). This combination seems to work on marine equipment fairly well. I did notice in the kit of spares is a bronze manifold but this would seem to carry the carb at a odd angle but is worth digging out and checking again. Thanks all for your input, I now have a few avenues to try.

I'm having a few teething problems with my 1930 Francis Barnet Black Hawk. It's proving difficult to tighten the Villiers carb onto the manifold. I had self amalgamation tape on originally but this  dissolves in the fuel. I tried a 1mm plastic sleeve which was too thick also .5mm thick shrink sleeving, also too thick. The manifold doesn't appear worn ( still has casting marks) but is around .5mm under size and the carb clamp can't close enough. Was there a .25 sleeve originally? Any suggestions gratefully received.         

Might be worth trying Russell Motors, Falcon rd, Battersea, london. They've been in business for donkey's years and bought tons of WD  surplus stock as well as dealer's stock as they closed down.

He's not gone, he keeps checking to see if we're talking about him.