The original taper attachment bracket that came with my Nardini 1440E lathe is a weak link in an otherwise good taper attachment. It is a little of 2" wide where it clamps to the flat way on the back of the lathe, and when in use, likes to creep, allowing the bracket to rotate. Not a good thing, so i made a new one which is about 5¼" wide and a little huskier overall, and clamps to the way via four 3/8"-16 hex cap screws.
Probably over-built, but I figure better too strong than too weak.
That is the original in the foreground and my new one in back. I made the new one from 3 larger pieces of steel, welded together at the same angle and relationships as the original. The distance between the center of the hole that the sliding rod sits in to the way, both horizontally and vertically, is all I really needed to pay much attention to.