I have received my sets and all I can say is that they are superb models with such attention to detail. I am very impressed with the sprung coupling pocket. A new standard to be extremely proud of. Well done again lads of the IRM.
Looks to me that the bottom and sides and one piece, so think the roof comes off with the glazing attached. So great care need to remove so as not to break, start in the middle and move along using wooden coffee stirrers to hold
Stainless Steel Scale Ruler and Handrail Jig is on offer at the moment at £14.95 from https://www.dccconcepts.com/product/stainless-steel-scale-ruler-and-handrail-jig/