I Have a German helmet that the liner is starting to fall apart and wanting to know if I should put a leather oil on it or replace it ? I sent a e-mail to a collector and seller last dec. but he never did reply .So I hope to get some feedback from here. and if this is a place to ask on this feed Thanks in advance
If the lining is original to the helmet then you should do all you possibly can to preserve it in place. Leather usually starts to deteriorate if it dires out ; it can help if you use some high-quality, non-dye, plain and colourless hide food ( available from harness/saddle dealers ) applied sparingly over a period of time.
These may be able to help you. The Online Guide to World War II German Helmets Particularly this section German-Helmets.com