Well gents, guess what? Yep. It drives. The rad just started leaking but it mthrfkn drives!!
Turns out it wasn't a backwards clutch plate. It's made in such a way that it only goes in one way. All dat junk hits the flywheel bolts.
So I decided to install the thinner PP. It was more 'f**k it' than logic. Do you know that despite all Mr. Toyoda's brilliance the trans can't be slid all the way back without it hitting the floor? Come on Mr. Toyoda, you're better than that! Anyway, cleaned all the grease some idiot put on everything, installed the clutch the same way I did last time, installed the new PP, then the gearbox fell backwards off it's carefully balanced perch atop my trolley jack [nearly ending up on the bitumen, which is sloped by the way] but the aforementioned floor stopped it from going any further. Thank you Mr. Toyoda for your brilliance! I'll never doubt you again old son. I used the now available space to align the clutch [by eye - who the hell uses a clutch alignment tool??] and get my TO bearing correctly installed as well as the fork. Things were looking good. Using the might of the J31 gearstick I levered the box back atop the jack and began inching to forwards. To anyone who's done this they'll know that this can be a complete PITA. Nonetheless we moved onwards and upwards. Literally upwards because of the slope of the street. Using my patented 'crouch, tackle and shove' method I actually got the box about 3" from home on the first go. I redirected my jack which had begun driving itself towards the gutter [thanks to the camber of the road] and the next shove got it close enough to get two bolts started. Got em threaded, adjusted the jack and got the last two bolts in before beginning to crank them all home. Got within an inch-and-a-half when I decided to pull the PP bolts to allow the clutch to align another whisker. Re-torqued them and then spent the next ten minutes using bolt power to bring the trans back where it should be. Got it flush, undid the PP bolts to reseat the clutch again, balanced myself behind the steering wheel and hit the key. It was a nice feeling to be looking down at that spinning handbrake drum through the hole in the floor as I sat on the bare floor like a six year old not going anywhere.
Needless to say I was quite chuffed at this stage, so I cleaned up all the drive shaft bolts and reinstalled the rear shaft. Left the front out to address that nut at a later date. Decluttered the front guards [tool benches

] and went for a 20 yard drive. There was a little clutch shudder so I rolled backwards down to my 'car park' and reseated [re-centred?] the clutch plate. Reinstalled a few more things: tank, driver's seat, my aftermarket oil pressure gauge, cleaned up all the tools from under the truck and drove it up to the end of the street. 50m this time. Turned around and then back down the street, past my house and around the corner before coming back again. A total of 150m! This may sound trite but I'm not well placed to be getting tow trucks every time something pops on this thing and it's fought me every step of the way. So 150m is pretty good I reckon. It's funny, it's like this 45 didn't want to be saved. I guess even old Landcruisers can be self destructive if they think they're too far gone.
So now it sits in the front yard under a tree until I can get a new rad in it and take it for a bit of a test drive. For the coming weeks it'll be in the back blocks only. I keep forgetting this thing sat for twelve years without turning a split rim in anger. Like anything that's been neglected that long the process of revival is going to be a gentle and lengthy one. Something I wish I knew last year. But by Jesus it's back.