Nice! Why does everyone else get the good finds?
They're rare in complete/good condition & will make lots of money like it. They're also horrendously fragile if you plan to use it & spares are expensive IF you can find them. I'd keep it away from the kids if I were you....
Battery-wise, you don't NEED the big pack, it'll work fine on a normal 6V one, but running time will be less. Don't be tempted to run it on 7.2V though, as you risk frying the "Electronic" speed controller (It's actually a transistorised electro-mechanical controller, & they can be fixed if you've got the know-how).
You'd be wise to check the radio set-up before running it too - a lot of people make a hash of it, & with the huge amount of slop in all the linkages, it really needs to be set up as close to perfect as you can get it, particularly the speed control (You don't want it running away or crashing....).
Main thing to watch for if you plan to use it, are the crappy flatted axle ends, where they fit in the alloy hubs - any kind of hard use will round them out & new/good ones are nearly impossible to find. Another thing to check is the bolt in the back of the gearbox that secures the idler gear to the front prop drive - these always come loose, get left loose, & chew up the 4x4 gearing, & possibly 1st gear as well. Make sure it's tight, maybe threadlock it too! Don't be tempted by more powerful motors either, they'll murder the axles as previously described.
The gearbox doesn't need a huge amount of lubrication, a few drops of thin machine oil every 3 or 4 runs is enough. Don't use grease or it'll start missing gear selections. I've seen people go to great lengths to seal the gearboxes up properly so they'll actually hold oil, but what that ends up doing is just keeping the gearbox full of dirty oil & metal dust, which will wear everything out more quickly. Have the rubber plugs out & peer into the bottom of the gearbox with a torch - there's likely to be black sludge & rubbish in there if it's ever been run. If it looks really bad, it would be a good idea to strip the gearbox & clean it out, but don't attempt this until after you've had a proper look at any info/diagrams you can find & you know what you're letting yourself in for!
The front freewheeling hubs can sometimes not "bite" & hold properly in the freewheeling mode, this can be fixed by having them apart & cleaning. Don't grease them, it'll make them worse, the internals need to be clean, grease-free & rattly to work properly.
Into the nitty-gritty.... if you look at the driveshaft set-up, you'll notice there's no sliding joints, which is bad when used with leaf spring suspension (As the suspension moves, the axles move in an arc, not straight up/down, so effectively get closer to/further away from the gearbox, but the propshafts are trying to stop this happening). Mr Tamiya thought the easiest way around this would be to rubber mount the gearbox, to build some "give" into the setup. SO, it's a good idea to check these rubber mounts are still flexible enough to allow easy movement, or you could end up breaking UJs. Sliding props would've been better (...& were fitted to later models). Oh yeah, & the UJ grubscrews tend to keep coming loose, so threadlock those as well....
