I'm sure you know, but for others, the Selle Anatomica Series 2 saddles have consumer-replaceable tops, and there's a choice of tops including tensionable weatherproof rubber. Note: Brooks England Cambium rubber saddles (made in Italy) do not have any tension adjustment.
Yes. thing is that I emailed SA asking for advice (rubber vs leather) and the exchange devolved into a complaint resolution script (different support staff interjecting at different points). I was in Europe at the time (touring) and was able to get Cambium locally, so I never closed the loop with SA.
Have you tried their rubber skin? If so, did it work for you?