fix for now
The inside diameter of the inlet hose is 5/8ths" so I put a piece of half-inch copper pipe at 5 and an eighth inches (an inch and a half for the removed valve, and the rest, the longest it could be without encroaching on the bends in the rubber), which seems to work out well, rounding the outside of the copper at the edge so it won't cut the rubber. Then, all happy-----then not-- after a few minutes of running it noticed a pinhole leak in the hose. This was probably the whole problem with leaking all along, and it never was the valve or the hose at the valve. So I ordered a fresh hose and while waiting for it used a hair dryer, super glue, duct tape and a hose clamp to repair the leak. A couple of hundred miles on, some of them highway, the reservoir is staying steady. My mechanic says the hose installation is not a cakewalk for a garage hack, and good luck with it. In the meantime, I do not miss the valve in nearly ninety degree Connecticut weather, driving with a couple of windows cracked, no A/C. I'm not even sure about re-installing the valve when I get around to changing the hose. The way I read it above in gsellstr's link @ "Some good info in here as well...
http://forums.turbobricks.com/showthread.php?t=246617," sending coolant through the heater core at all times means there is more "coolant flow around the backside of the head." This, to me, sounds like a good thing, so why really have a shut-off valve in the absence of A/C and if a little extra heat at the firewall is not a personal issue? I doubt this car will ever see California, though my brother's out in Guerneville . . . guess I'll keep the valve, just in case.