powdercoat is much cheaper for getting a frame done, not as nice as a good enamel but if it’s not for a posh bike it’s this hsould not matter. Should be able to find somewhere for about £40-60 ish.
RE: frame repair, there are lots of small frame builders all over the place who would do little jobs like this. I would ask at your local proper bike shop (i.e. old man with encyclopaedic knowledge of campag group-sets, central member of local club e.t.c) he / she will no doubt know someone who does simple frame repairs locally.
Alternately I’ve read that some mapp gas and a boss from ceeway would work. Never tried though only over used mapp on copper fittings for plumbing.