Difference for a surface grinder vs the mill is a very fine surface finish vs the milling marks from the typical milling tools. Assuming that the table is ground square to the wheel and it should be, you will get parallal sides as well and infeeds of .0001" on the wheel.
We have that same machine at the shop and the hydraulics to move the table is it downfall. If you can avoid it, do not take that control block apart.
The controls are fussy and the two are interconnected, turn one knob and you are turning the other to get the proper action back. Be sure to check the ways as lube is critical on this machine.
Did you get the pump and tank with it?
I may have some parts for the control block, if you are interested as the unit was removed a couple years ago on our machine.