My Wife and I are going over in September. She promised to take me to a nice sporting goods shop in exchange for sitting through a musical. Need some help here friends. Hope to take back a souvenir in the firm of clothing, knife, etc.
The London gun shops already mentioned are all very exclusive and top end, and I'd add Boss &Co which are quite near H&H as also well worth a visit.
Not sure about gunshops in Yorkshire, but if you PM me where you are visiting, I can make some enquires.
The only one that springs to mind off the top of my head is York Guns. That's a good size shop and a lot more realistic than the yuppy gunshops already mentioned in London. If you google them, they also have a decent website.
If you are anywhere near Leeds, you *must* visit the "Royal Armouries"..
Do a quick search on google and be prepared to trade your wife with another musical if needs be!
Regards,
Peter