Yes, that's almost exactly 7 ounces. I put that much in a totally dry fork, after taking them all apart and cleaning the insides out (and doing the Minton Mods). If it's a basic drain and refill, I'll put less in, closer to 6.5 ounces because, like you said, you never get all the old oil out. The only way to really equalize what's in both legs is to measure from the top of the tubes down to the oil level, springs out, forks fully compressed. I recently "tuned" my '83 forks by doing that. The 7 ounces I had put in seemed a bit much. The forks were a bit stiff and harsh over the little bumps. So I drew some off, setting the levels 6" from the tops of the tubes. I ended up taking about a half ounce out of each leg.
The adjustable top caps came along on the '78 models but I think only the U.S. bikes got them. I'm not sure about Canada. Europe and Australia didn't get them.