This is annouced by Doyle Lawson as the second annual Country Gentlemen Festival.
According to http://frobbi.org/slides/cg1972/ the second festival was held in 1972 at Indian Ranch, Webster, Massachusetts.
The Gents at that time were Charlie Waller, Bill Emerson, Doyle Lawson, and Bill Yates. 
Jimmy Gaudreau (a former Gentleman himself) was there as a member of II Generation. 
Date 1971-07-01 is probably incorrect.
Doyle Lawson does the introduction and he introduces Jimmy Bailey on the banjo... not Bill Emmerson.
On this slideshow (pictures of Fred Robbins) at the Second Annual Country Gentlemen festival - http://frobbi.org/slides/cg1972/ -
you see Bill Emmerson on the banjo... Mysterie.
The personel matches the band of 1978. So the correct date is probably 1978-06-30.


The Country Gentlemen
2nd annual Country Gentlemen Festival
Stuart, VA  - 1978-06-30


01 - Make Me A Pallet On Your Floor 
02 - Train 45 
03 - It's All Over Now, Baby Blue 
04 - There's A Star Spangled Banner Waving Somewhere 
05 - It's Just Like Heaven 
06 - I Ain't Got A Home 
07 - Rawhide 
08 - Fox On The Run 
09 - Tuning 
10 - Southbound Train 
11 - The C. G. Express 
12 - The Little Grave 
13 - Lord Don't Leave Me Here 
14 - Little Bessie 
15 - Bringing Mary Home // 
16 - // Banks Of The Ohio 
17 - Palms Of Victory 

Lineup
James Bailey Banjo
Jerry Douglas Dobro
Bill Yates Bass
Charlie Waller Guitar
Doyle Lawson Mandolin