1. Surely the long term plan is to not keep these relics in a gargantuan warehouse but instead to put them in a museum(s) — with free entry no less — so that the tax paying public can enjoy them.
2. Further, collections of relics that relate to the site of each station on the line could be displayed in each.
1. The permanent collections of just about all museums in the UK are free so if they go to a museum they will be free to see (after an initial exhibition if they were to host that)
2. This is not uncommon for things like Roman ruins in the UK. For example, near the Tower of London, there is a glass window in a random pedestrian underpass where you can see part of the original Roman wall around London, or in Cirencester and St Albans there are big parks where you can see all the Roman ruins. Where relics are smaller or more valuable, something like a railway station isn't really set up to keep them secure and on display so they would sometimes show casts or photographs of items, and have the original in an actual dedicated exhibition in a museum. For example if you go to Orkney you can see some viking relics in situ (eg the "viking grafitti" runes on the stones in maes howe) and some (like the scar boat burial) you need to go to an actual museum to see.