Rother Valley Railway

The rail for the Bodiam Extension was as is often the way with the K&ESR very complicated. The existing rail at preservation from just outside of Northiam station to Mill Ditch bridge (about 2 of 3 miles) was still S&ECR 91 1/4lb rail which required non standard chairs, keys and fishplates as it had a very different profile to the standard BR 95ib bullhead rail. At the time of the Bodiam Extension most of the fittings were absolutely shot and had to be disc cutted. Beyond Mill Ditch bridge the line had been relayed by BR with standard 95lb bullhead rail but much of this was on a type of experimental steel sleeper that by the time of the Bodiam Extension were rotted through.
At the time of the project EWS had a scheme to hugely expand the Uks freight network (all those class 66s that were never used) and this meant that secondhand rail absolutely skyrocketted in price and was limited in supply.
The project manager was able to source a minimum order of UIC rail from an Austrian Company which was cheaper than the price of UK secondhand rail at the time. This was actually as you have said milled in Poland. This was laid almost in its entirity with a few spares heading out from Northiam and extends to just past Padgehams Curve. It was laid on secondhand BR SHC clip sleepers, from there onwards to Bodiam its the "original" BR 95ib bullhead rail relaid on concrete sleepers. This is still the situation 25 years later.