Also you are correct I'm not aware of an email address for Keystone, but someone from there used to follow the 4L list on Yahoo. this is a logging list that tends toward rigidly prototype western logging modeling I still follow this list, but no longer contribute much , as they are dry and humorless, and look down on the lowly southeast loggers. so this would be another place to request help.
http://groups.yahoo.com/group/4L/
Looking at this photo of my narrow gauge coupler cheat, it appears there is room for a standard gauge coupler. the problem in the 3 foot gauge coupler sits lower, and they wouldn't clear the truck, and a Had to bump it out.
Another tricky part in the construction is fastening the covers on that hold the line shafts in place without gluing the line shafts in place. I got the truck frames and the covers cleaned up, and painted the line shaft with white lithium grease, and then used JB quick to glue the covers on over the line shafts. I used the same method on the build I did for Dr tom, and I torked like a charm on all four trucks, with the lineshafts held securely in place with little or no side play, and being able to turn freely in the truck sideframe.
Building this locomotive is a real project. The Keystone model was designed to be a static model. The NWSL kit allows you to turn it into a fine working locomotive, but it is not easy! I learned some stuff building this kit, and I thought I knew everything (I do now by the way). The Keystone/NWSL Shay, with the brass details cost me about half what I paid for the non operational PFM 25 ton shay . It took me months to build #2 and to tune the mechanism to my satisfaction. The PFM shay looks better, is more robust, and took me 15 minutes to fix ( tuner cleaner works wonder on the comutators of those old open frame motors.
again, any questions, I'll be glad to help. I looked in my railroad room no plans, unless they are in the nook that holds the dispatchers desk. I would need to get a new will and update my life insurance before I can disturb that pile!
Bill Nelson