I found the following information on the MK7 Shopsmith site. It does fit and will work:
MARK VII- Information
1960 Mark VII (7-in-1 tool)
Included a spindle shaper & dust collection system. The unit could be tilted in either direction. Plastic racks controlled Headstock movement. The MARK V Headstock will fit on the Mark VII frame (the plastic rack must be removed). It also has a plastic speed control that tends to melt with extended use. These units were NOT manufactured by Shopsmith, Inc. Shopsmith, Inc. has very few repair parts for these tools.
annbill.mayo wrote:Does anyone know if a Mark 5 headstock can replace a MK 7 headstock? Thanks.