RH - what is the reason for using the connector pins vice welding the base to the frame.
@YotaBota, the base has two V grooves: one is 80* included for the British Colchester Master lathe; the other side is a more conventional 90* included V for the Standard Modern 1340. So I undo 2 7/16” SHCS on the bottom, spin the base and put bolts back. I can use one base for two lathes. That way the opening of the steady rest always stays on the operator side. Otherwise it would be on the back when in use on the SM.
Another reason was that I figured if I welded the base to the frame after machining the Vs, the heat might distort it. I would then have no way to re-machine it. With the bolted, “cold”, connection, there is no distortion of the base so that the steady rest sits on the ways without any rocking. That in turn lets you use less clamping force as there is good base contact and nothing will move.