hi
once you get on to crepidotoid fungi, you do (with a few exceptions) need access to a microscope; bear in mind that there are several genera with this growth habit, though you look to have a
Crepidotus there
trouble is that there are around
20+ Crepidotus taxa in the UK and popular books have only a small selection (Phillips has 4, for example); and the characters needed to distinguish them involve spore shape and ornamentation, the nature of the cap cuticle, and so on
this thread might give you an inkling of the complexities of the genus:
Crepidotus query . . .
btw the current name for "C. lundelii" is
Crepidotus caspari
cheers
Chris