Ernie Shuttleworth was, of course, landlord of Beckindale's other hostelry, the Malt Shovel, and a long time rival of Amos Brearly. Ernie was not a regular character in the show, and was originally played by actor John Comer (on the right in the DVD cover illustration above), who also appeared as cafe owner Sid in Last Of The Summer Wine, and as Mr Brandon in I Didn't Know You Cared.
I don't know how many appearances Mr Comer made as Ernie Shuttleworth, but two Emmerdale Farm publications list him in the role - a 1976 special and the 1982 10th Anniversary magazine - although there is a printing error in the 1982 publication and the actor's surname appears as "Corner".
John Comer died in 1984. See his IMDB profile here.
Here's Amos and Ernie Shuttleworth mark II arguing it out at the Woolpack in 1986. Peter Schofield, who was a well-known face on UK TV, made sure that the Shuttleworth/Brearly war of the boozers continued to entertain. Remember him as Joe Dawson, the nasty cafe owner who reported Len Fairclough for not having a loo at his Kabin cafe in 1978? See Mr Schofield's IMDB profile here.
A brief role for Peter Schofield as unloved cafe owner Joe Dawson in Coronation Street.
I enjoyed the Amos/Ernie absurdities in Emmerdale Farm. I've just been revisiting some 1986 episodes with a storyline revolving round a dominoes tournament. Amos and the Peter Schofield era Ernie were at their absolute best, the script was witty, the acting superb and I was greatly entertained.
Happy days in Beckindale.