Thanks to all for the great advice, much appreciated !!!
I understand everyone's concerns about plumbing issues, been there done that ! One thing I have learned over the years', is know my limitations
If I think the issue at hand is over my head, I call in a professional.
Too often, in my younger years, when I thought I knew it all, I started a project only to get over my head, and have a situation worst off than I started
Will take a picture of the mixing valve, and bring to Trustworthy Hardware in Laconia. They're my local professional source. At least if they don't have the valve, they should be able to tell me the make/model type, and where I can purchase.....
Over the years, I've made friends in plumbing departments at both Lowes' & Home Depot, who are also in the trade, who I've have hired for small jobs like this.
Will circle back with results, after the fix.