[Eliot Ness]

The Tektronix 130 is certainly a nice piece of test equipment, but it doesn't appear to test leakage at the capacitors working voltage.  All you'll be doing is checking their values which many DMM's or cheap Chinese testers can do:

https://www.youtube.com/watch?v=fxqSa7NOAgQ

If you want to check the capacitors leakage you need a capacitor tester such as the Heathkit IT-11 (or) IT-28, a Sprague Tel-Ohmike, Jaskson 650, or Eico 950.  There are several others as well, but I mentioned those because they are relatively easy to find at hamfests, swapmeets, or eBay.  A key that the tester will check leakage is it will have a switch that will go up to about 500 volts.

Be aware that when buying a vintage piece of test equipment, just like a vintage radio, you'll want to replace the old capacitors and out-of-tolerance resistors.  If you buy a Heathkit or Eico you also want to check all the solder joints and wiring since these were kits and many were assembled by folks not used to doing such tasks.   Good luck, some enjoy collecting test equipment more than radios.  Below is a site you might want to take a look at as he discusses his views on various vintage capacitor testers:

http://www.ohio.edu/people/postr/bapix/capchkr2.htm