John:
Some 61's had remote topping adjustments built in, accessible from the cabin ceiling area, but I cannot recall if the commercial models were so equipped. Sure made this task easier.
Yes they are equipped. I was doing this as recently as this past summer and referred back to the company SOP we were using (140-2).
Even in extremely hot environments we would achieve topping with T5 margins (choosing an appropriate test flt altitude).
I believe from your notes above that your experience is on the Sea King. I am unsure which engine variant you are talking about, as it may explain our different experiences.