Well guys, I found the problem with the new IP cam lobe not being centered under the injector pump lifter. The new Cam lobe is drilled about 40 thou different from the original. (Please see pic) So much for Indian engineering.

Didn`t leave me with any option but to reuse the original. Annealed the old cam lobe, resurfaced it with a very fine file, followed by varying grades of emery cloth. It`s now about 10 thou smaller than the new one. Hardened it, then tempered it and a file won`t mark it now, so I think it worked out OK. I very much doubt that the loss of 10 thou will have a significant effect on either the injection pump or the oil pump although I wouldn`t recommend trying it on any modern high speed engines.
Machined up a new cast iron bush for the other end of the camshaft because the end float, due to wear, was excessive. (please see pic) I was about to cut the oil retaining groove in the far end of it to prevent oil from flowing into and puddling in the end cover when I had a revelation. The reason for the excessive end float is wear between the end of the bush and the face of the keeper which are deprived of lubrication by that oil retaining groove. So, instead, I have cut the oil slot in the new bush from end to end. (please see pic) This will lubricate the far end of the camshaft and keeper. The problem with this is that the end cover will fill up with oil. The solution is to drill a hole in the crankcase to allow that oil to drain back into the sump. I shall be doing that later this week and will post photos.
I managed to reassemble the camshaft, using the original components, I applied a couple of drops of medium strength Loctite to every cam lobe and taper pin before driving them in tight, I don`t want anything working loose, I don`t like surprises. (Please see pic)
Very disappointed, I turned a new offset spigot for the idler gear, I took a guess at 25 thou offset, no where near enough, I`m thinking 45 thou to get the gears to mesh well. I guess I`ll just have to make another.
Off to the doctors again tomorrow, so will try to post more on Tuesday.
Bob