I'm going leave you in the capable hands of ACE with this as he's dealt with these Terex models and knows them inside out, my last dealing with Terex...
Well you know your way round these much better than I, but thinking along the lines that to produce a fair quantity of them it has to be some biggish...
Hopefully ACE will be the authority for advise on these but in the meantime I can possibly fill in about question 1, caught ours where there was very...
As you've found a clean taper is top priority although the tang does also help with drive even though its more for the ejector key to push on during...
I expect if its the standard velvet shift it'll be just a switch on the F-R lever on the opposite side to where the control cable fits on a lever on...