Nah I think cleaning them up makes them look really nice. I have a soft spot for wood that's been worn and then cleaned up nicely. Do they seem to have any finish on them? Or are they raw? If they're unfinished I can heartily recommend using a polymerized tung oil to give them a protective coating. One that a company called Sutherland Wells makes is particularly high quality.
As for your earlier question: I believe that wooden chess sets were the standard back until plastic became widely used, and that price points reflected the species of wood used and the level of carving/turning skill required to make a set. Wood was generally seen as the "cheap" product until plastics became commonplace around the 60's, and stone/bone/ivory would have been likely used for high end sets back in the 20's.

















Thanks IBC…. Well… I hope I haven’t desecrated the set … but I’ll take the hit if I have … I have a day off work today and conducted the most delicate clean across the course of this morning.
I wanted to retain the patina but remove the surface grime … if that makes any sense. So.. warm soapy water and a cloth. …. Then bees wax oil applied with the finest 0000 steel wool and then… another two coats with a soft cloth. A light buff.
Honestly … I reckon the result is beautiful. The pieces seemed so ‘dry’ almost aching for some care … I don’t feel like I have lost anything - rather the pieces are richer and the aged/patina comes through with a renewed pride. In the flesh - it’s quite wonderful now and if I have offended any of the professional restorers here - I apologise in advance!
I have some excellent green English baize … I am very tempted to felt the bases but I’ll hold that idea for a while. I hope my phone photos do the pieces justice!