Does anyone have a trap with the John Ehn (as shown in the John Ehn methods) push pull trigger system (modification); it was originanlly described and used for muskrat trapping under ice with a number 3 or 4 trap then later added to the predator methods for buried bait and snow trapping.

The rat trigger system was mentioned in multiple 1940's Trappers Worlds. Tom Parr and reviewed the method of filling the notches on the pan and the dog in his copies of John Ehns Methods (file adjustments are on the sides of each, I also talked to John Houben about it also, he modified one of his traps to try it once. Neither have seen an early or original trap with it.

It may be possible that a Frank Terry or James Mast Trap may may have the modification. If you have one please post picture.