When Baxter discards the Stretch Hulk birthday present from his Dad in the bin, you can clearly see that it is a standard action figure, and not a 'stretch' toy.
In the end titles one song is named as "If I was a woman" the actual title is "If I was with a woman".
In the Kilburns' pub gig towards the start of the film (in the early 70s), the drummer is playing Sabian cymbals (a Sabian logo is clearly visible when the audience start throwing toilet rolls). The Sabian cymbal company didn't exist until 1981.