Uncommon: 1970's Johnson Bros. Trent Ware 'Trentline' Cistern w/ 1980's Ideal Standard 'Coronet' Pan

This is in a hotel which has a close coupled Royal Venton 'Shannon' or 'Coronet' (Coronet being early 60's with a rounded pedestal and side handle, Shannon being late 60's with squared pedestal and front handle) single trap syphonic in one of the rooms.
Sadly no syphonic on this room, we do however have a fairly uncommon Johnson Bros. Trent Ware 'Trentline' low level cistern, paired with a 1980's Ideal Standard 'Coronet' washdown pan. So at least we know this didn't replace a syphonic RV!
The only original part of the cistern remaining is the handle, with the syphon being a newer Fluidmaster one, and although the ballcock is newer, it's still a part 1 and gives a great refill with plenty of stuttering and hisses, and towards the end it almost sounds like there's a plane flying overhead with a deep bass stutter.
Surprising also that the Fluidmaster syphon provides a brilliant flush, the best I've seen from one of these at low level, slightly swirling with a great glug at the end. I've put together a paper flush and cistern view too :)