I always thought of the Threepersons as a holster for a single action. Not that it can't be used for other actions, but given the SA as a starting point the relevant criteria for me is the exposed trigger guard, exposed hammer, forward cant and a high-ride.

The Wolfram pictured would not qualify as the hammer has too much coverage. I picture a Threepersons as exposing a great deal of the revolver at the top.

My hands-down favorite would be the Lawrence 120. The Myers is right there with it.