Once you’ve passed the early collecting stage you should be able to easily spot a fake liner. The aged ones are slightly more difficult , watch for strange stains on the leather – abnormal oxidation on the liner band – low quality leather – unusual folds. Original liners have a typical “old” smell that cannot be duplicated. Newer or aged liners will have a more chemical smell or new smell.
If you flip the leather check out the felt , most reproduction liners have white felt which makes it really easy to discard them as reproductions. Original liners have a grey/brownish color and a different texture.
In most cases these liners are reproduced for re-enactors , as peoples heads have become larger small sizes are less prone to being reproduced.
The maker marks stamped into reproduction liners are taken from the original makers but the quality of stamping is lacking and the font is often wrong.
NOTE : Most reproductions are all single band and thus steel liners.
Here are some pictures of liners that are sold as reproductions.