Mike,
It is indeed an op amp. Most of my databooks and datasheets on this kind of thing are at the shop, but the part was a lower-cost general purpose op amp I think and I'm guessing that its specs weren't all that much different from, say, a 741. It uses standard analog supplies of +- 15 volts and you'll notice it has a ground (common) pin. This was pretty much the rule in the early days of op amps. Even the first analog IC's had ground pins: The 702 op amp, the 710, 711, 720, 820 comparators and others had ground pins. For the trim pin, generally you would connect a resistor, maybe a rheostat-connected pot, perhaps 50k or so, from the negative rail to the trim pin.
I don't know what the input common-mode and differential voltage ranges were or if the output is protected or not. If you are wanting to fire it up and the pins haven't been soldered to, there are plenty of nice ways to connect to them without goobering them all up with solder. If they're still pristine gold-plated pins and you don't want to scratch them up with socket connectors, you might use wire-wrap wire and wrap them by hand. The pins are round, of course, and too big for a wire-wrap tool. Wrap with at least an inch of wire. I would then slide something like a piece of insulation from 14 ga wire or maybe some heat-shrink down over it. (This was called "spaghetti" in the far-flung days of yesteryear.) I would leave the heat-shrink unshrunk, though. If it's tight, you (or someone) may have to cut it and scratch or damage the pin. There were standard sockets available, too, by the way.
I haven't been to the shop for a few days. It's been 20 below here for a few days and I've been working from home. I should get down there in a day or two, though, and I'll try to find the datasheets for these things.
Dave Graen