[Attachment(s) from rigmatch@... included below]
Maybe a design for carriage for a small lathe. "attached". Only 2 bolts attach the cross slide base since there probably not be room for more. The cross slide would be aligned over wet grout and then removed after the grout stiffens.
The cross slide base would be tapped for 2 through bolts that would pass through the narrow carriage center section and be used to attach a larger lead or concrete "dumb bell" weight on the bottom.
The cross slide base would then be epoxied into the "socket" left in the grout.
In this way a large cross slide could be securely aligned and attached to a narrow but heavy carriage practical for even a 6" lathe.