You can get the right foam for these midrange drivers from this company in the Netherlands:
https://speakerrepairshop.nl/nl/luidsprekerranden-van-foam/overige-merken/foamrand-voor-elac-4em-101-middentoner/a-3036-10000028#.WKxuwlUrJhE
I used the kit from these guys to re-foam my drivers a few...