An update, gentlemen. As stated earlier, I measured .004 bed wear. Further inspection reveals another .006 in the underside of the carriage. Shim under gib here adds ANOTHER .010.! Far side of back ways worn .004 at the headstock. Small wonder I found a little chatter.
So- I have spent some time measuring, and scheming. I built a scraper and jig. Disassembled the carriage, and used it, with careful gib adjustment, to guide my progress. "Y" play is now consistent full lenght. Carriage vertical, "Z" I believe, has been reduced to .004 at headstock, to nil about halfway towards tailstock.
Is it RIGHT? Absolutely not.
Is it RESTORED? Well, kinda.
Is it BETTER? By a whole bunch.
Was it tedious, satisfying, and CHEAP? Oh, my, YES!
Please know that all of your input was considered thru all of this. I did a test run on a scrap piece, on the mill, as I originally had proposed. As Brino kindly suggested, "A bit ambitious"...Not a small understatement, gently delivered, greatly appreciated.