The original middle and rear seat had carriage head bolts mounting upside down on the bottom feet of the seat frames. The heads went into key-hole shaped slots in the floor. A wing nut on the threaded part of the bolt was used to tighten it up.
I've got a '62 and use it as my daily driver. It's a rough old primative truck, but I LOVE it.
The front suspension is a torsion bar type front end. Only used on 1960-'62 trucks. It's expensive to rebuild these using stock replacement parts. If you're handy with tools and somewhat mechanically inclined, you can convert it to a later coil spring type front end without too much difficulty.
If you plan on upgrading the brakes to front discs, it's expensive on these trucks because the clutch uses hydraulic clutch linkage, with a fluid reservoir. That reservoir needs to be taken into account when upgrading the brake master cylinder. In '63 they went to mechanical clutch linkage, doing away with the reservoir. From what I understand, it's a pretty common modification to convert to mechanical linkage. Brake kits incorporating the hydraulic clutch are availalbe, but more expensive.
The '60-'63 wrap-around windshields are 2-to-3 times more expensive than the flat '64-'66 windshields ('60-'63 is usually about $350-$450, plus shipping).
Finally, the middle and rear seats for these trucks are very hard to come by. So are the original 60/40 split bench fronts for that matter.
So are the window latches for the sliding side windows.
However, in the year I've had my truck, I've bought a full-width middle row seat, latches for the two sliding side rear windows (some trucks had all four side windows that opened), a front 60/40 bench that needs to be completely rebuild, and the hard-to-come by original 6-bolt steel wheels. I've also found two rust-free/dent-free doors, a solid front fender, two rust-free innner fenders, and a complete tail and lift gate assembly to replace my barn doors. And I've done it on a very, very tight budget--around $500 for all of those pieces, sourced from many different places. So it can be done.
If I had it to do over again, I'd probably look for a '63, only because of the torsion bar front end. However, I really like the way the T-bar rides, so I'll bite the bullet and rebuild it. Should only have to rebuild it twice in my life time.
-Brad