I wish the BBC would show the whole of that Bob Monkhouse last ever concert in front of fellow comics. Looked good and has never been shown. Here's some more that have very rarely been repeated or never at all!
Dear Ladies (Hinge and Bracket)
Kelly Montieth (BBC show, was it good I can't remember)
The Pall Bearer's Review (never been repeated on anything BBC2 controversial Jerry Sadowitz show)
Filthy, Rich and Catflap (underated Young Ones follow on)
Seven of One (Ronnie Barker pilot of Porridge and Open all Hours etc)
Hot Metal (one of ITV's really good sitcoms)
Peter Cook and Company
End of Part One
Hancock (hasn't been shown for ages)
You Bet Your Life (US Groucho Marx show)
Jack Benny Show
Till Death do us part
The Fenn Street Gang (sequel to Please Sir)
A few of these have been repeated, Seven of One was on GOLD last year - blink and you'd have missed it though! Filthy Rich gets an airing on Dave every so often. A lot of the old Granada Plus staples you listed like Please Sir etc didn't make the jump to ITV3.