We are now selling motors, power supplies, and New hot-ends for 3mm filament for our machines as well as yours. The new style 3mm hot end has a one nut mounting feature, makes for easy removal and maintenance. Could be adapted to your x-carriage. Also we now have teflon tubing in stock for replacing your liners. More to come, even an H-2?
Any chance you have a 3D drawings of the Steve's extruder, or top view outline? From the looks of it, Im not sure it will fit the vertical X on the printer I will be building.