Simplest is to use that transistor tester in the cheapie multimeter, and simply take a bag of transistors and bin them for gain, being sure to handle all the devices as little as possible so they do not heat up, and choose 2 in the middle of the spread. Generally good enough for this application, and in general the manufacturer of the dual devices mostly used 2 chips from the die next to each other in the assembly, with the premise that being next to each other on the wafer they probably were pretty closely matched anyway.
A lot of equipment manufacturers would simply buy a lot of transistors, put them all in a jig that held them at a constant temperature, and get a few parameters out of them after a heat cycle to even them out, then simply put them in bins selected for the parameters desired. That is why you often see in older HP and TEK, along with Phillips, the transistors with a paint mark on the case, with the parts that were gain matched, typically differential DC amplifiers, all using a same colour transistor per stage, and with all being the same base type. Often they were selected for either gain within a narrow range, low leakage or for voltage rating, out of the big pool of raw devices.