Morris Minor Owners Club

Ok, so any know when bronze trunnions were discontinued. I managed to pick up a set at an autojumble this year - now earmarked for the '49 saloon. Presumably they were replaced with steel ones due to cost, or was it wear rate?

Three trunnions on my 1952 saloon were bronze - one had been replaced by a cast steel one. The car was original and with just over 50,000 miles on the clock.
Bob