Update: I took my machine to Steel City Mower and Plow on Tuesday. They seemed receptive to do the work, and thought they would be able to look at in the "next day or two," depending upon snow. Clearly, they have a good snow plow and spreader business, and are dropping all else to service their customers with these products. We discussed what might be the problem, thinking the leak was coming from an oil seal on the bottom on the engine.
Since they were going to probably have valve covers off anyway, I asked them to adjust the valves. Also, I asked them to replace the fuel line. I've read too many threads on LS about fuel line failures because of age, ... spilled fuel, fire, end of ZTR. I could have done this, but I was sure they had stock fuel line.
Yes, ... young folks, there!
I received a call late this afternoon, "... Z-track is ready to go." I had enough time to get my trailer hooked, and get there before they closed for the day.
The machine was ready to go, as promised. They quickly discovered the oil was coming from one of the valve covers, bottom side. They replaced the gaskets, checked the valves (no adjustment needed at 1830 hours, adjusted at 500 hours a couple of years ago), and the problem appears to be fixed. Yes, it was a task that I could have done, and probably would have discovered the problem if I had done a valve adjustment.
They also replaced the fuel line, so I feel better about having a new, supple fuel line, one that has no rubbings on it either.
Bottom line: I think they did a fine job. Time will tell if the oil leak is solved in the long run, but seems to be fine now.
They could have followed my idea, removed the engine, removed the pulleys and clutch, replaced the oil seal on the bottom of the crank, AND cleared up the valve cover problem. I would have gotten the machine back, no oil leak, and thought they fixed the leak with the oil seal replacement. AND, I would have been paid much more money for the repair -- never being the wiser about the real problem.
Thanks again for the tip. I would return to them with another problem, and would recommend their work to others with engine problems.
Just for reference to others, they do sell SnowBoss plows, large V-hopper and endgate salt spreaders, SCAG mowers, Husqvarna equipment (mowers, hand power tools, etc), and Ventrac tractors. I left with the impression that they have done well with SnowBoss (they offer 24 hour emergency service). They are at Rt 88 and Connor Rd, Castle Shannon, right between Rt 88 and the trolley tracks.