The main reason for scrapping the trams in 1930 was that they had run for some thirty odd years and the cars and track were worn out. The cost of replacing the system like for like was far more than replacing with buses. I have a piece of the track recovered from Dock Road and it is well worn in profile. As far as I know, no new, replacement, cars were added to the original fleet, except when needed for the Rochester extensions after the Chatham / Gillingham sections were opened. The last new trams were delivered in 1911. In 1928 a second hand car was bought from the Maidstone system but it was by then over 20 years old and Maidstone scrapped the others of the same batch at the same time.
Buses were cheaper to buy and operate and were more flexible in operation, not only could one pass another but routes could be extended where and when required with out digging up the road!
Finally, as a child C1955 I seem to remember, I think, seeing a tram body in use as a shed in a garden or field somewhere between Stoke and All-Hallows. Can anyone confirm this, was it a Chatham car, or was I just dreaming it up?