The instructions I gave were for the pins of a socket 7 tube. The principle is the same for any tube you just have to identify what each pin is connected to. The best place to take measurements is the most convenient to your setup so the breadboard connections would probably be best.
For me, it is easiest and most convenient to take these measurements off of the 7-pin Vectors because no matter what tube I use, be it 6DJ8, 12AX7, 6SL7 or 2C51, the measurements are taken at the exact same pins, namely 2, 3, 4 and 5. If I make measurements at the 9-pin socket, I have to pay close attention to how the two triodes and the heater are connected, as they are slightly different for each of these tubes. But of course, YMMV. :)