Three Keen Boys in Mustard

I had to give these three names, so from left to right, let me introduce Derek, Barry and Jeff, circa 1972.

Derek is being terribly ostentatious, holding open his AA Handbook and dangling his car keys.

Two things trouble me about this pattern.  Why does it say "Double Knittings" instead of "Double Knitting"?  It looks like a bad translation...

... but Lotus Wools were in Leicester.

Also, one of the trio is sporting a glaring knitting error in his mustard creation.  Can anybody else see it?