I wonder would a more radical approach be to make a new, smaller layout (possibly also with better scenery) and rotate use of the trains. Thus, a visitor could end up seeing Enterprises of 1947 and 1970, with a Donegal train chasing a T & D one on the narrow gauge bit on one visit, and on another visit a DART, a MGWR goods train, a Causeway tram and a pair of 121s with a Craven set!