1. Get Engine Running and desmogged.
Yep, if you run into snags there, the whole plan falls apart. Focus on that like a laser.
3. exhaust. Jeff said "check - Note that OEM muffler/tailpipe is (was) still avaiable from dealer for about the same (inexpensive) $$ as aftermarket muffler shops, and it bolts right up!" So I just give Stevinson or CDan a call and order it up??
Whilst the muffler and tailpipe and all brackets and hangers/hardware were still available last time I ordered them in new from Stevinson, the down pipe is not! Make sure you have a down pipe!
4. check and overhaul brakes. another call to Stevinson or CDan and have beer as a bribe for help.
New shoes are readily available from the dealer. Cylinders are sketchy if you want new ones. I know the ones on my 71 are no longer available from Toyota but ones for my 76 and 78 are. I've had decent luck with CCoT's cylinders for my 71.
5. gas tank. have a couple. need to take to Denver Radiator (?) and have them checked and maybe boiled and sealed.
Definitely will spoil your plans if your tank is either full of crud or leaking.
IF I can get all that done...
1. Either move locker from FJ55 axle to the 40 or throw on the whole axle. Would involve some more brake work as that axles has the brakes stripped. No hurry for the front disc brake axle as that would add a lot more time.
Again, my advice is to prioritize this lower. As Ige noted, moving the diff or just the locker (assuming Lock-Right?) is MUCH less work than the axles housings, it's still more to add to the above.
Wish list
Wish list
4. sliders. if SROR has some that are ready quickly, cool. If not, won't worry about it.
As I wrote, 40s really don't need them, that's a wagon thing. If you bash up your running boards some, whatever, who cares? All the years I've done Moab I've never messed up my running boards. Bashed 'em up pretty good on local trails though, but nothing a BFH can't fix.
One last bit of advice. Stare at the rig a lot. Mentally note what's not there and let your eye wander around your garage for what you have, and don't have, so you know what you'll need. Like bolts for the tranny to bellhousing (and yokes to driveshaft - they're special bolts and nuts). Little crap like that is such a time sink if you don't think about it in advance. Fuel line, heater hose, gaskets, air cleaner, so many details. Make a list! Be more specific! Like, for the exhaust, you'll need the donut (gasket) that goes between the manifold and the downpipe. And nuts and washers! Etc.