Great info! Thanks. What is the difference between a sg and sg48? I bought a green belt from mcmaster that looks right, but I havent tried it yet. I'm refreshing a emco 7 mill/drill first.Sorry I am just now seeing this. I got a rubber belt from Sopko and Sons. It took a week or 2 to get it but in the meantime I decided to go to a vacuum cleaner store and see what they had. Sure enough they have exactly what I needed in many different lengths. i installed the Sopko belt and it runs super smooth. I never installed the VC belt but I doubt their would be a difference. Vacuum cleaner belts run pretty fast and take a lot of abuse so I am sure they would be able to put up with the dust from surface grinding.
As for the chromed surfaces on your SG (not an SG48), I believe if the bottom surface of the cross-slide is chromed it was done for the purposes of wear resistance. As to wether thats a good idea or not, I am not sure.
The tapped holes on the side of the column covers was probably for measuring fine downfeed of the spindle. There was probably an indicator mounted in some fadhion and those items are now missing. Thats my guess. I made an indicator mount for my SG to read spindle downfeed in tenths. There was to ways of going about making a mount and I think whats on your machine is the method I didn’t use but now in hindsight might have been better.
The indictor idea is a good one. I can try that later too.