It’s been bugging me so I made the effort to track down where I’m pretty certain I first saw mention of Iain Banks – a review in Imagine magazine (a role playing / D&D mag put out by TSR UK in the mid 80s)
It’s in issue 29 (August 1984) in the Fantasy Media review column by a certain Neil Gaiman (then credited as writing the Imagine short stories: 'Feather Quest' and 'How to Sell the Ponti Bridge' and co-author of Ghastly Beyond Belief)
The review in full: Iain Bank’s (sic) THE WASP FACTORY will delight horror fans with its mixture of black humour and horrible, imaginative, beautiful deaths.
That's where the journey started, I picked up a copy of the paperback in Smiths soon after...