If your happy to use Indian cloned parts, are comfortable to handle the import aspects, and want to save some money etc, then why not give these people a try:
http://www.devprecisionengineers.com/As they seem to have all the contacts.
Even though the Lister CS 3-1 was never made for the Indian market ( just like the Lister FR, CD, CE, and JP range of engines), most parts specific to the 3-1 engine are readily available via the Indian route if you know where to look.
Another solution for you to consider (if your not concerned about non-originality). Is to fit a crank from a later Lister CS 5-1, 6-1, or 8-1, because the crank is interchangeable with the 3-1 connecting rod. The extra 0.250" increase in crankshaft big end diameter on the big end is taken care of by having a thinner wall Steel backed big end shell bearings, instead of the thicker walled bronze backed bearing you have on your Lister CS 3-1.
As the Lister CS 3-1 uses a Bronze backed bearing, have you also considered re-metaling the shells that you already have, a temporary solution I have seen used too good effect on a twin cylinder Russell Newbury diesel engine was to re-metal the big end shells with plumbers solder and a blowtorch (and the canal barge this engine is fitted to is still running ten years later).
If your set on using OEM parts, and your crank shaft big end journal is still within the roundness tolerance at STD size, the PM me as I have a surplus pair of NOS OEM STD size Bronze backed bearings, that I would let go to a good home. They are not perfect, as they have a few knocks and also has some light oxidation on the white metal from years of storage, but with a little TLC they could be used with no problems.
