Made a bit more progress last night, but reckon the job is going to take a lot longer than I thought. The material is pretty tough and, I suspect, thicker than the norm to counteract the smaller diameter. Hopefully I'll have removed a significant strip or two of pillar tonight! Maybe the going will get easier when removing the alloy from the carbon fibre, as near the top the post's corroded onto the frame lug - which is also alloy.
At this rate, though, can't see the bike getting a competitive outing for the remaining Thursday TTs this summer
Dave B