Shower Control Valve

I am back at my mother's house again 2 hours away, fixing her tenent's shower valve. It is a 3 knob control, hot-diverter-cold control valve. The cold water valve stem need replacing. I cannot figure out what manufacturer makes the valve control. I have a detail drawing after I made some measurements. Sorry, no photo, just the attached hand drawing.

From the drawing, is it possible to figure out what make it is? Home Depot plumbing guy is looking at it like it came from mars. I'll be trying plumbing supply store next. I cannot bring the stem with me to the plumbing shop for any extended time. It still works some what so I have to install it back while I go hunt for the stem.

HELP !

Unfortunately even with a good clear picture matching is tough...
Often matching is a combination of things that add up...
The handles, escutchions, and stems combine to give a solid ID...

I was ready to cut the old shower control out and solder a new unit in. Of course, things are never so easy. I cannot get the water to shut off tight. Water continue to drip. Looks like the shut off valves are pretty old too. With my luck, the main shut off will also be leaking.

SO ... At this point, the current stem is still working. The spine for the knob is a bit shewed up. It is not an emergency, YET! I have to keep looking for the bonnet & stem replacement.