I once had a Paul G. Mehlin & Sons "Inverted Grand" from about 1915,
with a double-valve Auto-DeLuxe player action finished to match the
piano's mahogany exterior.  The quality was above average and it turned
out fairly well with less than a complete rebuilding.  The tone was
more or less what you would expect from an upright in that price range,
in spite of its having a bass bridge of an unusual design.

Many piano makers who didn't make their own player actions bought them
at different times from various manufacturers.  So one piano might have
a Standard Pneumatic Co. player action, while another instrument of the
same make could be found to contain a Pratt-Read, and so on.

Mehlin didn't make a lot of pianos.  Comparable quality can be found
in a Chickering or George Steck, to mention but two better-known makes.
Condition is still all-important: factors such as loose veneer and
other bad glue joints, extensive tuning pin rust and severe moth
damage, all suggest a piano that may not be worth acquiring unless it
has exceptional potential.

Jeffrey R. Wood