Is the Model 22, Model of 1917 an N-Frame?
The first N-frame was called 38/44 Outdoorsman. It was a 38 Special mated to the 44 Hand Ejector frame. Creating a large, heavy, wonderfully accurate 38 Special for heavier loads. The 357 Magnum was a pretty direct decendant for use in the heavy frame. These were the 'Registered' 357 Magnums.
Both are highly collectible. The N-frame has been used for calibers from 38 Spl to the 44 Mag.
Here's a couple 1917's for you.