Two different designs of bearing were used on early Round bed Drummond lathes. The first  had separate upper and lower sections with the clearance set by shims. Whilst the holding-down and adjustment screws are original the screw-in oil caps are not.

The second type of early bearing was formed as a single piece with the clearance set by a slot and pinch bolt (the two large bolts in the picture should have a single slot across their tops - not hexagon sockets). The large set-screw to the left bolts the cap down (assisted by two little screws at the right-hand side) with bearing clearance set by the large set-screw on the right.

Another view of the second bearing type - in this case showing evidence of having been clamped in a rough-jawed vice.