That's quite a good idea..........It will certainly be unusual (I guess I need to get a couple of West Country based Sentinels covered off first). There's a few possibles here; Industrial Diesel Locomotives (eastsomersetrailway.com) Industrials (Including Narrow Gauge and Steam.) - TomCurtisRailGallery I particularly like the shunter with its matching BG on a works train at Matlock. (Might try and recreate that).
There are some strange beasts among that lot! Shunter seem to come in many shapes and sizes. Some are almost skateboards!
A good turnout at the WSR Sentinel gala despite the rain. The demonstration WSR Works train has just pulled in to Blue Anchor behind the home-based 'olive' Sentinel & "Betty" whilst a passing Minehead bound passenger service is in the hands of 'guests' from London Transport and the NCB.
Ha ha, I knew you wouldn't be able to resist! Good work. Typical English weather for a Diesel Gala!!!