The five iterations were:
The original model, with either back action or front action. Very few made.
Second model with two piece lifter and top pin indicator. The latter modified at some time to delete the top pin. Some were returned for this change.
Third model was the one piece lifter with a wedge forend attachment.
The fourth was the one piece lifter with a forend release.
The fifth was the fourth model with a modified barrel lug system.
There are transitional examples found between some of the models. Also, the frame was altered a couple of times to improve strength.
