Re older models over the last 9 months or so I've bought from Palava, Eponine, Oska, Batsheva, Klements, Liberty, Cabbages and Roses, Dicks of Edinburgh, Monsoon, Lanx and Baum und Pferdgarten.
Apart from Batsheva who use Batsheva Hay (43) as a model and Oska (see below) none of them have models who look over 30. Eponine has its founder, Jet Shenkman (60ish) on its blog wearing her own designs but not modelling them.
I'm struggling to imagine that any of these brands have a big foothold in the under 30 market.
Are they scared if they show older models it will put off younger buyers? Or is it the other way round - if they use older models will it scare off older buyers - who may well be the actual buyers and the ones with cash? I don't know the answer to this but I'm pondering what my own reaction would be if there were older models or older models were in a majority. The Oska model, Batsheva Hay and Jet Shenkman look great so I think it would make no difference if there were a good mixture of ages. I confess if all or the majority were older, I'm not so sure.
Palava is particularly surprising given they, with justication, make much of their ethical credentials, provenance of materials and makers, small runs, slow fashion etc so not being ageist should be right up their street.
Oska older model