Often the simplest changes are the best. Here’s perhaps two of the easiest that can be applied to the Bachmann Mk1 Sleeper…..
As supplied, the sleeper comes with B4 bogies (okay they should technically be B5’s but that’s for another day). The use of B5 bogies covers the first 79 Mk1 second class sleepers (SLSTP) numbered 2500 – 2578 however the remaining 113 of the 192 built were equipped from new with ESC Commonwealth bogies which they retained until the vehicles were withdrawn or scrapped.
The Commonwealth bogied vehicles were numbered 2579 – 2691 and if you want to add a bit of prototype variety (for both the BR Maroon and BR Blue & Grey versions) these are quick hit. Fortunately (for it makes the swap somewhat easier) Bachmann sell them as spares (Part 36-008A) and replacing them is a simple matter of unscrewing those supplied and swapping them over with the Commomwealth type.
Finally for this round, another relatively simple change. If you want to model the sleeping cars as they were seen in service (certainly late at night and into early morning) the vehicle wouldn’t be complete without the blinds or shutters drawn. the SLSTP, SLC (including the first class compartments) & SLE conversions were equipped with light grey roller blinds, and the SLF, first class vehicles were equipped with light grey sliding shutters on the berth side only – and on the berth bodylights only. After having removed the body from the underframe unit, the “blinds” in this case are represented using plasticard inserts, spray painted light grey (and measuring 10.5mm x 7mm) which are pressed into the recess at the rear of the glazing moulding, and simply taped down Of course it might be easier to remove the glazing and just spray the appropriate sections however at least by using inserts, they are easily removed if you change your mind!
You could of course model some berths without blinds, some half drawn and some still fully drawn – all on the same vehicle – typical of how the sleeping cars looked when sitting at the destination or on there way out to the carriage sidings!