After being quoted a very large sum of money for fitting an adjustable comb (no judgement implied, I'm sure it would have been a pukka job), I've decided that I should have a crack at it myself.
So I would really appreciate any hints, tips or tricks that any of the members might have, especially if they have done this themselves. What are the major pitfalls and things to look out for?
Also any suggestions for pre-made fittings (I have seen a few on the bay) would be welcome.

I have three guns which could do with the treatment - Diana 54, HW95k, and possibly also a Hatsan Striker. The last rifle could be a good one to start off with and practice on as it's a cheapie, but because of that it may not be worth the investment?

All advice welcome