Grips
I know of a coach who will alter yours to a perfect fit, but he is not your area and would need to see you. The result is perfect but not pretty, I am not aware of any UK grip maker who is worth using on a match target grip.
The best bet is Rink, look on his web site, he has enough measurement criteria to get them right. You are better to deal direct, he is not fast or cheap but the results are worth it.
If you have or can get contact to a good coach they will also advise the criteria that suits you.
You do also have Harry and Sue Preston in your region who coach the national Juniors so a phone call to them might be worth a call.
Best of luck
Robin
Walther KK500 Alutec expert special - Barnard .223 "wilde" in a Walther KK500 Alutec stock, mmm...tasty!! - Keppeler 6 mmBR with Walther grip and wood! I may be a Walther-phile?