Hopefully, not too taxed after the start. You need the number of these objects from part 1 = ABC; decipher this (using part 1) = D; no. of Opens (from plaque I sent you to in part 1) = E. If you haven't been to the plaque / can't find it / are doing this from home then try looking for the number of Opens the original professional from a nearby club won.
(Have had a couple of people getting wrong number for ABC - only one number will decipher using part 1, and it's got a neat local connection as well).
By the way, Walton Heath also has the unique distinction of being the only club in England to have had a reigning monarch as its Captain, when the then Prince of Wales became King Edward VIII during his Captaincy in 1935/36. Was going to use that as part of the clue, but too easy!
Cache is at 51.1E.(CBA + D squared) 0.1(A+B).(CBA + E squared)
Raised difficulty and amended clue based on feedback. If it annoys too many people going forwards, I will add more clues!