VPK Autographic Special 1915-1926.
Perhaps the most usually found Autographic Special is the one fitted with the f8 Rapid Rectilinear non-focussing lens. These are everywhere so cameras in excellent condition can usually be inexpensively found.
The most expensive VPK special when new and often when purchased today is the famous focussing f4.9 Zeiss Tessar mounted in an 8 speed Compur shutter. Highly collectable!