I have never received a viable submission from an older model. There was one woman a few years ago who was in her 40s or so, and she was bummed when I told her I don't accept sets of 5-ish photos. (I require, and spell out clearly, that I must get 50-80 photos.) She was not discriminated against on the basis of age, I told her I'd be happy to see a real submission in the future, but never heard from her again.
If you want to see some "older" porn, make some "older" porn, plain and simple.
This reminds me of the unconference I was just at where a bunch of different people were loudly criticizing the conference organizer for not having various _____ panels, but ANYONE could do a talk and the whole thing was organized on an email list.
No one has any room to complain about anything they aren't taking steps to remedy.