Quite a productive weekend so far and extended my familiarity with certain operations and problem solving.
Started on the replacement Drive Shaft. For anyone interested, I took images of the sequence to make it. Clamped a length of 3/16" dia Silver Steel to enhance the angles/line of the original drilled 'Lock Pin' hole-
I was then able to use the Rod to set up on the Lathe, so a Ball Nosed Slot Drill would mill the radiused groove along the correct line. The Rod checked first against a Face Plate, then against a set of precision Parallels and 'V' Blocks laid on the Bed Ways-
Offset was only about 2 degrees from parallel along the Shaft (arrowed), and about 4 deg on the tilt from vertical (obscured by spanner) -
Finished machined Shaft along with the old one for comparison-
Some careful measuring and prep before pressing the shaft in to ensure the two parts with the partial holes line up worked ok-
Pin pressed back in ok and happy with the result. Well, with a 12 ton Press sitting in the Workshop, it seems a shame not to find any work for it.