I have a '63 Farmall 560 wide front I'm bringing back from the dead, running well now but still under restoration. The 460/560 was a very well-designed midsize tractor with lots of "modern" features like multiple hydraulics and power steering(!), lots of engine power with great low-end torque, relatively easy to get mechanical parts. Sheet metal parts and such have been much harder to find.
The mechanical suspension seats found on this series are really expensive to repair. Unless you are restoring it for show, consider replacing it with a more modern mechanical (not air) suspension seat, possibly out of a heavy truck salvage yard. You can also order them from the Northern Tool website. Northern also has replacement IH cushions if the seat mechanicals are OK.
I've had to do a lot of research on parts, etc. because there are very few sources of old tractor components in my area of the country. All you experts out there correct me if I am wrong, but I think the 460 & 560 share a lot of driveline components. My understanding is that the early years of production on this series (1958-59-60?) had serious problems with the TA, leading to a major recall by the factory. This problem was fixed for later models which were in production through 1963. I would check this out carefully, checking for serial number vs. when the problem was determined at the factory, to see if this is one of the affected tractors. IF the tractor and/or TA was not used hard, there may not be any problem. Is it possible to determine if any TA recall repairs were done, or if that model had any of those TA problems to begin with? That mechanic may be able to help with these issues.
This may affect the tractor's value significantly. I've driven tractors of this type where the TA was totally shot, and they seemed to drive fine in upper-range gears, although I did not attempt to pull a load with them. I passed up several older 460's and 560's until I found mine, largely because of TA problems. A lot depends on what you plan to do with the tractor. Running a mower is a lot different than plowing all day or pulling stumps. If possible, operate it under the anticipated load, to see if things really work. Check out the archives on this message forum, there may be a lot of info on the TA problems, as well as other stuff related to the 460. Sounds like a good tractor, just be fully informed to avoid nasty surprises.