Had a go at keying out (in Funga Nordica and Fungi of Switzerland) this
Inocybe growing on calcareous soils under Beech and came up with
I.sindonia:

Spores: smooth 9.3-10.3µ x 4.9-5.6µ
Cap: up to about 30mm, pale at first darkening and breaking into scales later
Clamps: present within pillipellus
Stem: pale, pruniose throughout length
Cystidia from top of stem:
Cystidia from bottom of stem:
Gills: darkening with age, basidia four spored, both cheilocystidia:
and pleurocystida:

present
I realise this is a difficult genus but as this is reported as fairly common I wonder if anyone is familiar enough with this species to confirm it.
Thanks as always.