Pre-war Derby autographs

[derby1884]

Well out of touch with what these kind of things are worth now.
Any advice appreciated.

a) 1931 - 8 x 4" card, 29 Derby players & management autographs (in pencil)
b) 1934 - 5 x 4" card, 12 Derby reserves. Autographs obtained prior to (or after) a reserve game at the BBG.
c) 1935 - 6 x 4" card, 7 Derby players autogrpahs obtained after home game with Arsenal (or, so I'm told).

These all look genuine to my eyes. I suspect (b) and (c) were collected by the same person.
I got them at an auction circa 1981. Forgot I had them until I stumbled upon them last week.