Now I am really wondering what sort of grinder this is. A surface grinder would use spindle bearings,

You haven't spent much time in a real machine shop. There are grinders and then there are GRINDERS. A bench grinder is what your talking about with bronze bushings but today most of them have ball bearings.

This is what the TS is talking about -

 

Even my old Kwik-Way valve grinder has spindle bearings in it, like this one(but not mine)

 

You haven't spent much time in a real machine shop. There are grinders and then there are GRINDERS. A bench grinder is what your talking about with bronze bushings but today most of them have ball bearings.

This is what the TS is talking about -

View attachment 198913

OK, evidently I only worked in a different kind of machine shop, which was used for building indutrial testing machinery. I learned to run both the LeBlond lathe and the Bridgeport mill, also the bandsaw, and the rotary blade chop saw. Not bad for an EE, do you think? Knowing how to use them assured that I could have the needed dimensions on the mechanical designs that I also did. I also used a surface grinder a few times but mostly the mill. That is an incredibly versatile machine. And how many folks can wind half inch stainless tube cooling coils on a lathe? I developed the arrangement for that at one place that I worked.