Done. 
I was just over at lomascan’s place, set his router DNS, then put additional servers in Network Manager. Tested the repo connection and all works as it is supposed to.
The only thing I do not know is if his IP address has changed in the meantime, so that might be another possibility.
For any of you who want a more informed way to choose DNS Servers, I suggest you try out the tool from Gibson Research, DNS Benchmark.
It runs under Windows & Linux. In Linux, if you double-click on the DNSBenchmark.exe file, it will launch under Wine (of course, you need Wine installed first). Just follow the directions, and additional reading is at their website. I use it all the time and it gives me speedier and more reliable access to the internet. Give it a try.
You can get the utility here:
https://www.grc.com/dns/benchmark.htm