A number of us have asked Weaver Models to consider producing a NYO&W Light Mountain In Mountaineer Livery. I believe they need some more encouragement. The 405 was a light mountain styled by Otto Kuhler just prior to WWII. I will post a picture later. The O&WRHS has Alco construction documents and one of the members has photographed and measured the original tender type and has offered his services and research to Weaver. You can contact Weaver at: customerservice@weavermodels.com
Here's a copy of the email I sent them. If you are interested feel free to use it or modify it to meet your need.
I've recently had correspondence with Paul Lubiner and he mentioned that he offered to assist you in the development of an O Scale NYO&W Mountain 405. I would purchase a 405 in the Mountaineer livery and a second in standard configuration with a different number in it's class. This is a distinctive loco that would also interest brass collectors and other modelers of Northeastern railroads as the O&W interchanged with the NYC in several places and with the NH, Erie, LNE ,LHR D&H and LV. I would urge you to consider this locomotive as future release. While I am a 2 rail modeler I believe this loco in Mountaineer livery would do well with 3 railers as well.