Barnes: "Cartridges of the World", 8th ed provides the following dates for
regular US production.

1857: .22 short.
1871: .22 long ( sane bullet, longer case)
1887: .22 long rifle ( same case as the long with a heavier 40 gr. bullet)
1880 - 1935: .22 extra long.
1890: .22 winchester Rimfire (WRF) very popular  and common here in Alaska.
1903: .22 Winchester Automatic ( larger case diameter)
1914: .22 Remington Automatic (similar to Win. Auto.)

References worth finding:

Barber, J. L.  1987  The Rimfire Cartridge in the United States and Canada,
Armory Publications, Tacoma, Washington, USA
Suydam, C.R.  1977  The American Cartridge.  Bordan Publishing Co.,
Alhambra, California, USA
Kass, George   Rimfire Headstamps  (this is by memory, probably faulty,
have the book at home, e-mail me if you need a true reference)

Of interest in your case is that Barber states that American production
switched from copper case material to brass in the late 1920's.  I would
guess about the start of thre great depression, 1928 or so.

Also, my work with these things show that careful measurements of the
firing pin depression; its orientation, shape and location can provide
insight into the least number of weapons and sometimes the type of weapons
used.

hope this is of some help

Charles Adkins