What about a special service for Navy personnel, passenger and/or freight?
Put a pannier on the railtour trio, job done! Truth be told, they'd probably bus personnel from Yeovil. Several pictures of Yeovil Town have Navy Bedford buses in the forecourt - Bedfords, I think they were. This sort of thing:
Freight is a different matter, I have a couple of opens marked down for crates of various kinds: does anyone know the sizes of '60s aero engines?
I've found that using an actual working timetable from the area being modelled can be all you need. For example looking at the FoD branch timetable in the 50's there were sixteen trains a day. If I ever get round to building this layout it will be all I need and is varied enough for me.
Obviously you can add or delete as required, but the bones of a real timetable are pretty useful.
For my Dublingham layout, pinching the Peter Denny timetable resulted in 15 trains per operating session. I generally get through three timetable cycles during a show, operating as fast or slow as I want and it's plenty of excitement.
Tony
How about this, Westlands, rotors, 1/144 scale, Wessex HAS1 View attachment 220646