In case it helps, I finished the job this weekend.
A couple things went sideways, but that's to be expected for a novice mechanic
. All's well that ends well.
I was concerned about the sleeve insertion and did some additional research. Found a document on the ZF that specified 3mm gap between the sleeve collar and transmission bulkhead. It seemed like mine was firmly inserted and clicked in with the locking tab, but the gap was greater than 3mm, so I devised a press (using a big socket) and pushed some more until this happened:
I figure the o-rings are the wear item, so I swapped the new o-rings from the busted sleeve into the old sleeve and inserted until tight (disregarding the 3mm spec). The 3mm spec must be generic for the ZF, but LR3 must have a bit more gap.
The other little challenge was that I de-attached the transmission lever to allow more room for removing bolts. And when I re-attached the nut for the lever, I must have torqued the transmission lever into gear. When I tried to start the engine to suck in tranny fluid, the engine wouldn't start and wouldn't release the key. I only had to re-align the gear lever, and then re-tighten the lever, but it caused some anxiety. With the vehicle in park, it started right up and I could proceed with filling transmission fluid.
Anyhow, all working now. Took it for a test drive and all fine. I'll drive it for a week to ensure no leaks before putting on the heatshield and skid plate.
Lots of fresh fluid in the old girl!