There is only one dealer that I know of that is in the UK and that is Super Mirrors. As far as I know Sead (Super Mirrors) does not work on reps, but just deals in them. Contact sead1999rg@gmail.com
For watch repairs and some light modding I use SSTEEL (Micky) in Finland. I've never had much modding work, so can't help you there, but others will put you right, and some research on this forum will also help.