I have this grinder too, mine is badged was a Rockwell , and in a surface/tool and cutter grinder. Great tool!!!
Mine has a removable spindle ,but yours has no picture of the spindle with the cover removed. I got one spindle with the machine and made 6-7 more (tricky project) so I can swap rocks without having to redress the stone every time. I have a couple boron nitride and several diamond wheels. This tool gets used more than I would have thought. I have build/bought fixtures to sharpen saws, reamers, build acme threading cobalt tools, ect. It is a dandy tool . There is a trick little tool to remove the spindle. I can take a pic if you need it.