The easiest / cheapest option will be to get a new carb bung expander kit with a 'standard' to cap as opposed to looking for a top cap which will fit the Reynolds expander that is in place and take a weird screw on top cap (Similar to the LOOK ones btw).
Since the steerer is carbon, the longest expander the best.
On the Lynskey? That was really lucky!
The easiest / cheapest option will be to get a new carb bung expander kit with a 'standard' to cap as opposed to looking for a top cap which will fit the Reynolds expander that is in place and take a weird screw on top cap (Similar to the LOOK ones btw).
Since the steerer is carbon, the longest expander the best.
Skint:
http://www.planetx.co.uk/i/q/FSPXFBUMK2/planet-x-carbon-steerer-fork-bung-mk-2
Minted:
http://www.chainreactioncycles.com/colnago-fork-expander/rp-prod70234