Matt
Only recently started exploring this facinating area myself and it has already paid some handsome dividends. Try and get a copy of British Planemakers from 1700 by Goodman ( not easy to find, apparently 3rd ed is best and most comprehensive, mine is 2nd ed). This lists a wealth of info and gives samples of the makers marks and an indication of their rarity.
For instance, I can't find any reference to Curries of Glasgow (are you sure its not a Ford Dealership/

), so this might be worth following up. Some makers are worth quite a bit as collectors like to have sets by the same guy etc
I just got a hollow by Gabriel in amongst a lot I bought at Ledbury which I hope will pay for the lot by itself. Fingers crossed.
Alf seems tohave forgotten more about this than I will probably ever learn and has been a great help.
Regards
Martin