I love your photo collection of Camelbacks! Thanks for posting.
I grew up in Dunellen, NJ, location of the CNJ engine terminal and coach yard 26 miles from Jersey City. Mom would take my brother and I to the station in the evenings to pick up my dad who was a union electrician working mostly in New York City, and therein the origin of my love for the CNJ and those wonderful hulking, steaming, hissing Camelback 4-6-0s that brought dad home to the family!
As a little kid, I went for my lungs with my allowance savings and purchased one of the Aristo 4-6-0s back in the early 60's. In college and afterwards as a business heavy traveler, I never had the time or space for model railroading but now in retirement I want to bring back Dunellen and its Camelbacks, so I've acquired via eBay a collection of mostly broken Aristo 4-6-0s and am seeking to restore two or three to running condition.
My question for you is whether and how you might have re-powered yours. As you know, the original Aristo motors were open frame, mounted vertically. Their "height" above the diecast frame surface was just 27 mm - a tad over 1 inch. So while I originally thought I'd replace the motor with a re-positioned can driving the lead drive axle rather than the original driven axle #3, upon evaluating that change, it would require machining a new opening for a gearbox. It would also require altering how the boiler would be attached to the chassis, since a new motor shaft/gearbox would be in the way of the original mounting screw and receptacle inside the boiler. Moving that boiler mounting screw location aft might not be possible because it might interfere with axle #2.
So, all things considered, I thought it would be easier and more practical to replace the original motor with a can motor mounted vertically with the worm directly engaging the original geared axle. That said, given the concave interior shape of the firebox area, there really isn't 27 mm of vertical space above the frame surface. I might get away with a 25 mm motor (with plastic end cap removed) but that seems pretty small in terms of power & torque.
Being very familiar with this particular model, I wonder if you had any thoughts or experience on re-motoring it. In any case, thanks for the great pictures!