identifying the signal on the Dolores Colorado Depot Porch Roof ???

   They have the very same signal at the Colorado Railroad museum depot.  If no one here knows ,I know just the guy to ask at the museum this weekend.

Similar to the signal,  East Broad Top railroad, Orbisonia Station.

My Orbisonia, BTS model.   Note the lantern top, red and white boards bottom, turned by hand.

That signal indicates that the train has to pick up orders at that station. Most of the time the operator will hand the orders up to the train as it passes by without the train having to stop.  But if the orders are not out to be picked up, the train has to stop and the crew goes in the station to pick up the orders. 

David is correct. It is a train order signal.

There appears to be a Grandt Line Kit. in O-scale.

I believe that is specifically a Swift train order signal. NP used these on branch lines and one can be seen at the Snoqualmie, WA depot/museum. The signal provided two indications, stop (red) and proceed (white or green). Some also had a light at the top with similar indications for night-time visibility. 

At some stations, NP sometimes needed a third aspect (i.e. "Form 19") in addition to STOP ("Form 31") and proceed (no orders) aspects. For a Form 19 yellow aspect, NP operators would set the signal to the STOP position, and hang a yellow lantern from the signal. There was a hole drilled in the outermost "paddle" of the signal from which to hang the lantern.  (A Form 19 order does not require the engineer to stop the train in order to receive it. They were typically hooped up on the fly to the engine crew and conductor.) 

This is very Helpful, Thanks to all who replied

Bernard