I lived in Denver until last year and never found a tech that knew
reproducing pianos (there are almost no player techs at all there!)
I was the only person I know of that serviced Ampicos or Duo-Arts and I
only did it as a favor to other collectors, not professionally. I live
in the Bay Area of CA now, otherwise I'd be glad to help.

There is a player tech in Loveland, CO who knew players pretty well, but
did not specialize in them.  I can't think of his name though.  You
might also call Chris Finger Pianos and ask for Chris 303-652-3110 (near
Boulder).  Chris knows most of the piano techs in the area, and he may
be able to recommend someone who will work on your Duo-Art (he bought
my Knabe Ampico and was well aware of what a reproducer is).

Hope this helps,

Scott Currier
http://www.currierandives.com