This ain't EXACTLY proper garage, the term for a jam of this MAGNITUDE is the '60s term invented in the '80s: freakbeat. Th term "freakbeat" was invented by collector/complier/label owner Phil Smee to describe beat music as it evolved away from 12 bar R&B into what would be psychedelic and progressive. The Mickey Finn's "Garden Of My Mind" is a prime example of this evolution.
Originally known as Mickey Finn and The Blue Men this group formed out of East London R&B band the Strangers... after developing a taste for ska. The band became The Mickey Finn in 1965. In all they had six 45s, eventually splitting up in 1971. There is an American Mickey Finn, they're a terrible novelty group.