I'm handy with most jobs but haven't treated damp myself before.
Kitchen wall has rising damp.

I'm going to drill size 12 holes into the wall and inject a damp proof
treatment. It's a Victorian house and has double walls - do I keep
drilling though to the internal brick wall as well (obviously not all
the way through) Or do I just get to the gap and inject into there?

A friend had the work done (he's in Bedford) and couldn't believe it
when he paid hundreds of pounds and the bloke came around and drilled
the holes, put in the filler, and left almost as quickly as he
arrived. The holes drilled there were about 50cm apart. From what I've
read, that's too far apart. Has he been diddled, or is a little
knowledge worth that much these days?

I won't do the internal re-plastering though. The previous occupant
already made a hash of that. What sort of quote should I expect (in
London) for replastering - 1.5, high (to be safe) x 2 metres wide?
I'll take the existing plaster off myself (anything else I can do
before the plasterer arrives to make his life easier and mine
cheaper?)

Thanks.

Geoff.