Ipswich Transport Museum [https://www.ipswichtransportmuseum.co.uk] has a rich and relevant collection of vehicles and other transport material illustrating public transport and the emergency services from a local perspective.
There is a horse tram from Cambridge (1880), an Ipswich electric tram (1904), Ipswich trolleybuses from 1923 onwards and Eastern Counties motorbuses from 1927, together with emergency-services vehicles and a particularly fine Daimler hearse,– all housed in a well-lit former trolleybus depot at Priory Heath.
The collection covers local tram, trolleybus, motorbus and coach operators and the versatile Ipswich manufacturer Ransomes, Sims & Jeffries,– and features the Ipswich Corporation fleet, distinctive for long, narrow destination indicators and unpainted aluminium body panels.
One vehicle resonated for me though I’d never before visited Ipswich. Eastern Counties LK374 (KNG 374), a 1949 Bristol K double-decker, carries a lowbridge body, a feature I had as little to do with as possible in my 1960s travels in the East Midlands.
Double-deck buses up to the 1950s sat much higher on their chassis than later vehicles, because the lower-deck floor had to clear the rear axle and transmission shaft.
The only practical way of reducing headroom to run a double-decker under bridges of restricted height was to align the upper-deck gangway with the offside windows and sink it into the lower-deck ceiling.
This meant that the seats upstairs had to be four across, with obvious inconvenience and increased dwell-time when someone by the nearside window needed to alight. It also meant that anyone seated downstairs against the offside window risked bumping their head when rising from their seat.
My Derbyshire schoolmates who were obliged to ride on these things called them “coffin buses”.
We hated them.
There was, eventually, a solution, but it was a long time coming to many bus operators…