Saw this on another forum so thought id post it up here in case its of use.
Might try this to repair the bottom drain plug thread which has split (and therefore very leavy) in my villiers clutch cover.... the video is very impressive
Ive got a lammie campagnolo disc brake that stripped the thread from one of the studs, and it wouldnt come out so had to drill it out and I never got round to getting the hole welded then recut (cause its a left hand thread as im sure you know..), so id be interested to hear if it works
I have some villiers casings that need some repairs so i will try it on them. I also have a few spare chain casings if you are stuck for one. Also you should use a drum front brake on your lambretta, i got fastest lap of the meeting at three sisters with a s2 drum.