you might  try E-bay there are several on there site .  Just type in leather fire helmets and there are usually 2 pages of helmets the may range from very old to like new and in poor condition to like new . I seen one on there that was from back in the 50s but had never been used ,it was selling for over $1000.00 . Most of the prices are very reasonable . I hope this helps .   

I just checked on e-bay the old helmet is from 1950s or early 60s 100% original never used buy it now for $1195.00 with no bids . Item # 360326392571 . That sure is a lot to pay for an old helmet , the only person that I could think of that would pay that much for a helmet would be a die hard collector that would have roots in the dept. that the helmet was from . Anyway to make a long story short there are some nice helmets on e-bay just look very close to what you are bidding on and you could get a real deal .