I've got for sale a Thomson seat post and stem in black. Pretty much the best you can get and I'm only selling as my new bike has the same on it already.
Seat Post- 410mm long and 27.2mm width. In very good condition with only a little bit of rubbing at the base of the shaft and one small scratch on the post. £40 posted.
Stem- x4 version. 1 1/8th, 100mm c to c with a 10 degree rise. Very good condition with only a small mark on the clamp. £35 posted.
For reference, sold as a pair for £65.
Feel free to contact me for more pictures or information.