Lovely job so far.
What did you use to remove old powder coat? I have couple of bikes with powder coat with which I am not satisfied and want to remove it so every advice is welcome!
The seatpost is now out. It took the best part of two days and I used three tubs of caustic soda. Holes were plugged with blu tack and taped over to stop the solution going anywhere other than inside the seat tube.
It's a messy job and I'm glad it's now done.