Hi Nik,
I don't own a 464 so I will answer this question in a more general sense.
You will probably have some people tell you a 464 is not worth repairing or calibrating because of how cheap and/or easily it is to acquire a working one in good condition. I beg to differ. Recently, I bought myself a 2230 which is also an analog scope (although it does have some digital capabilities). I bought one specifically in non-working condition because while I have used oscilloscopes for years now, I had never done an extensive repair on one. I wanted to use it as a learning opportunity on how an osilloscope works and the circuitry involved. An analog scope is the perfect tool for this learning experience. Also, these older scopes tend to have incredible service manuals with tons of information on theory of operation, repair, calibration, and schematics with representative waveforms.
While I encourage you to repair this scope, it can be a dangerous enterprise. There are voltages >1kV present due to the CRT. So you have to be careful. You should read the service manual thoroughly before approaching this project if you wish to do so.
Calibration of an osilloscope can be a complex and expensive endeavor. But it depends on what you want to do the calibration for. If you are looking to do it more so as a performance check, then you can get buy using alternative equipment (like a known working/accuracte function generator) to do some of the tests/adjustments. You will also need some decent RF cables, attenuators, and terminators (50ohm, 600ohm). The good news is that the service manual provides you with a list of all the equipment you will need to perform the calibration. You can review this list and decide what you need. Now if you were calibrating this scope to be used an accredited ISO lab, you would want the proper equipment outlined in the manual to perform the calibration. And all that equipment would need to be calibrated as well. So this is where it gets complex and expensive. Things like TM500 series and its plug-ins (calibrator generator, pulse generator, time marker generator, leveled sine wave generator) are required. But again, for a hobbyist, you can replicate what a lot of this equipment can do with cheaper tools. It really depends on why you want to do the calibration.
I hope you plan to revive this scope. For me, working on this 2230 has been a great experience where I learned a lot.
-Frank
Frank Mashockie