Diaphragms for passenger cars

I have several Tenshodo ATSF passenger cars vista dome & coach. I think they were manufactured around 1958-59 time frame & represent cars operated in the early 50s. My problem is they had foam rubber diaphragms which have rotted & have to be replaced. Can anyone tell me which diaphrams would be most accurate for that time frame. I don’t want to use more foam rubber. Thanks for any info.

I use these on all my passenger cars:

http://americanlimitedmodels.com/index.html

They were out of production for a while but I believe they are available again now, or will be soon.

Sheldon