reaming seattube on 753 frame

I have a reynolds 753 Peugeot frame with 26.6 seatpost size and I 'm kitting it out with dura-ace. I can only find the requisite seatpost in 26.8. Would it be silly to ream out the seat-tube by .2 mm or beneficial for better fit? Would I damage the thin walled tubing by doing so?

If the consensus is to go for it, who would be able to do it in London?

are you sure its 26.6 they are usually 26.8 or 27.2 ,i wouldnt suggest taking material off a 753 tube it will weaken it and crack