Tony I am not sure when HC got involved and what he did, didnt do. At a guess Id say 2 is his probably the 4th too and 12 is clasic colt but his stamp might be bunkering of the course rather than routing.
I did a new routing for Bath in about 1994 but it was more ideas and did not get used. The club wanted two nines and could acquire/ or had acquirred a bit of land left of 1 and 2. We came up with a couple of schemes to get two nines (its currently and 11 and 7) and a hole we created we then found out was an original hole from the 40s that got lost, it linked the present 5th to todays 15th. I think the 14th, the one Mark mentions as the quarry hole might be more recent, 11 might be newer, the 6th is different now from when I first played Bath, it used to be a long par 4 dogleg right, now its a 5 doglegging left.