For reference, climbed in 4 pitches, hopefully this description helps others.
P1, 50m, Climb the lowest right facing groove at the base of the buttress (just inside Douglas Gibson gully) until easier ground and another right facing corner takes you up the buttress.
P2, 50m, Move on to the crest of the buttress and continue up until a step right can be made in to the base of a steep left facing corner. Continue up this and then towards the crest by the left groove, thread and spike belay just below the crest.
P3, 50m, Head for the crest right below the tower, where there is good exposure looking down in to Douglas Gibson. Approach either by continuing up from the belay and moving over the big flakes or by stepping right from the belay in to the first left slanting corner. From the crest step & reach over to a shallow groove on the tower and pull on to the tower face (difficult under powder since there is a slab for feet). Continue up the face of the tower heading for the sentry box (trending a little right then left). Pull with difficulty in to the sentry box. The sentry box is a bit tight for a winter belay and the crampon/face risk is high so continue up and out on to the ridge proper. Continue along the exposed ridge (for 20m) until it begins to steepen again and belay here. Note that the “groove on the right” at the base of tower in the guide book is not the groove round the right hand face of the tower, the route tackles the tower direct.
P4, 60m, from the belay move up and round in to a steep left facing corner, continue up following the line of the ridge until another final right facing corner leads up right to the summit.