Long time since I saw this, so all I remembered really were the quotable bits ('We've gone on holiday by accident!')
The high dinginess and run-down state of Britain as the sixties ran down is skilfully evoked. It's very male, though. The only female character is the woman in the tearoom who refuses to serve our heroes. If that's the right word.
It's not laugh-out-loud funny, but it has aged surprisingly well.