Scottlep,
I live in Springwater, NY about an hour north of Tioga, PA. The challenge to put a slide racker on a Steelmaster is the lack of material between the breech face and the top of the slide. Its about .410 and I dont know if that leaves enough space for a dovetail.
STI has a brand new cylindrical slide racker thats featured on the new DVC Steel models that might work. Its positioned at an angle with an angled hole opposed to a dovetail. I'm no gunsmith, so any suggestions would be a huge help. Thanks for your time and consideration.