I can't find info on the "crashbox" but there are enough similarities to the SM420 to at least guide me a bit. I found some sweet manuals on the SM420:
https://kinzers.com/don/landcruiser/transmissions/When I opened the tranny... moisture. It appears the trans may have been opened before - about 1/3 of the top-cover gasket was missing. The previous owner said the truck sat in the garage for 10+ years - even the clutch had frozen to the pressure plate by this time. So it's no surprise that the tranny is a little locked. Luckily it seems to be superficial at this point. The shifter itself seems to have gotten dry of gear oil and suffered the rust. I think I can get things freed up again (PB Blaster, wire brush, elbow grease).
With any luck... I'll have her moving around my driveway this weekend!!!
Here are some pics (in the event you see something)...
