Fine Arts Models vs Lionel Smithsonian NYC cars

I have replaced my dried out rubber diaphragms most of them on the FAM cars with latex sheeting. The models are identical in construction finish although different names. I've bought several for transcontinental sleepers. A must including on my PRB Coast Daylight cars is to use Zymöl "Seal" rubber conditioner and preservative. It works wonders and will revive them even if they are hard. As long as they are not broken they will soften up and come back. It actually makes them operate better especially on my Daylight cars.

The rubber in the diaphragms is breaking  on the Lionel car.  What latex do you use?

Thanks

The Lionel and FAM cars are essentially the same, so the stuff Erik recommends for FAM would work. Both names (Lionel and FAM) were imported by the late Gary Kohs, who sold stuff under the Fine Arts Models name. They were all built by Sun Jin models of Korea. Sun Jin was the main builder for George Kohs, Gary's brother, aka Kohs and Company, for several years. There is a product called Armor All (automotive stores) that is also pretty decent restoring/preserving rubber.

The FAM stuff was sold independent of the Lionel name to the best of my knowledge.

Simon