Shame you weren't around when I had my mishap James, back in Oct 2010. At the time I had 3 options. Local LR dealer £2600, well enough said, local well known LR independant, who were willing to remove box, take it to auto specialist, then re-fit, 3 days without car, £1600 or the same auto specialist to do whole job at £800, 1 days work. They said they fully inspect all aspects of the box, replace any suspect bits, refill with the correct oil "by the book" fully road test in auto and steptronic for 40 miles and then give an unconditional 12 month guarantee.
30 years ago I had gearboxes out of MG Midgets, Triumph Spitfires, etc in the ol' mans garage for mates, knackered synchros, bust clutches etc, I'm past all that and dont have the space, time or facilities any more. I was well happy with the service I got and, to be honest, the price I paid.
I wont be undoing that bolt again, but if the box should go after the guarantee is out, I'll get you to give me a quote, lol.
Best regards!