When I was restoring my old bike I found those gumi inserts are realy crap beacouse of years and years of use. I just made new ones (need 4 of them) from ABS, that was printed by a friend. They are not soft, but I need some UV resistant material. I will try with some soft 95A material on my printer later.
Those pedals was used on Steyr, Stiria, Puch and also some other bicycles from the late 1950's onward