Hi wilbur,
Interesting stuff. I have only worked on one Greenie with a diff lock fitted and I didn't have to do anything to the diff lock apart from making sure it worked. Most of the Greenies have direct drive, meaning bot rear wheels drive all the time which makes steering a bit difficult. I'm wondering how you replace the bearings on the shafts with the welded flanges, but I guess there is a way of doing it. And the welder will work fine with 60m of lead
Anyway glad you are getting it sorted, they are a good machine, just keep up the maintenance and it will last as long as you need it