I have 2 USE 25.4mm posts in black.  One is mid 90s with the yellow, red n green sticker.  This has lighter patches where the anodising has been rubbed by a saddlebag and the other is a Y2K with no sticker in good condition. 
I also have 27.0 and a 30.8 shims for the posts.  Both seatposts are 400mm long
£20 each and shims are free.