Vintage Gopher Piston Tool Ring Groove Re-Cutter, Re-Groover Missing Blades

This is a very early automotive engine tool, the Gopher Piston Tool manufactured by the Northwest Machine and Tool Co of Minneapolis Minn. I would estimate it is circa late teens. Everything on the early auto engines wore out quickly, including the piston ring grooves which became wider, and this tool was made to cut the piston ring grooves slightly wider so oversize rings could be installed. Tool is about 13" long, looks complete except for the cutter blade or blades, which fed in from the top end of the frame, pushed into the grooves by a knurled knob. An interesting example of the type of tools used on auto engines in the early days, but not usable unless a new cutter blade could be fashioned, which would not be that difficult as it is a fairly simple device.