Thanks for all the tips folks. I checked the intonation last night using my electronic tuner and the 12th fret harmonic method that Clinton and Rick recommended. Very happy to report that everything was either spot on or just very slightly off.

Graham, I'll try your method of checking EADGBE at different frets and see if I'm still in tune.

Amazing that my acoustic is a two hundred dollar used "beater" holds tune and has a lot less buzzing than my electric (I know that is a poison word here) Gretsch Nashville which cost me a small fortune. Maybe it's time to send the Gretsch in for a professional set up.

Thanks again for all your help.