P&WV 2-6-6-4 in HO scale - planned project

Hi;

Has anyone tackled making a model of the P&WV 2-6-6-4 locomotives?

I have been planning one for years, but have not yet found the time to start on
the project. My inclination is to use a PRR M1a/M1b boiler as a form (and I am
looking for one at a low price), shortened Mantua 2-8-0 chassis, with gearboxes
from a Mantua 2-6-6-2.

Any suggestions and sources of information would be greatly appreciated.

Thank you
Nigel