Looking over John Tuttle's four images of pouch setting tools
[180418 MMDigest], I recognize #1 as being the model sold by
piano supply houses.  I'd be interested as well in hearing of
anybody's experiences with that particular design.

I suspect designs #3 and 4 would be preferable, providing more
of a safety margin in case of pouch shrinkage.  Perhaps with the
gentle curve in the first design there might also be a chance of
interference with the edges of a lifter disc or wooden valve
button.

Richard Friedman
Upstate New York