Hi Vinyl,
I live on the other side of the planet and have owned a pair of DMT 15 which although are not an exactly the same, the sound signature is very similar.
The Westies use the "old" pepper pot HF unit, rather than the straight wave guide in later Studio models, which do have a slightly smoother or averaging frequency response.
I used to be the Tannoy agent in NZ prior to Tannoy being sold from Harmon to the now string of other companies.
Luckily, the "timber range " of speakers are still made in the UK with the same attention to detail and craftmanship.
I sold my only pair to a diamond dealer from South Africa who I believe never really used them, they where a piece of furniture to him.
I used to have in-house frequency response graphs for most models and can remember the WR does have a smooth "harmon curve" in the HF range. My Australian general manager had a pair of GRF memories. When visiting, I spent a few night listening to many types of music.
Like many Tannoy horn speakers, the efficiency with Bryston amps (we were agents also) I learnt quickly how a room interferes with the over all sound at the high SPL these models could devour.
Im not sure what you have been quoted $US but they are around $80K here in Australia.
I know the dealer here would probably export to the US which would mean you could at least discount the local 10% sales tax.
Good luck finding someone to get a real in home demo which you are very astute to do.
Spending that sort of money, the pleasure is in the search and auditions as much as the satisfaction of finally listening.
All the best
Anthony