Cheers guys, for now I’m just going to cut two strips of cardboard by marking round the blade and tape them together. Will probably line it with some more tape.
Those plastic bonding glues take me back to my days working on plastic pipe work for vacuum sewage systems, we used Methyl Ethyl Ketone paste and slotted the pipes together so the plastic fused to itself. Get it wrong and you'd be hacksawing the mistake out.
Ideally, something like the plastic A4 binders, but in the right shape should be provided, like the ones that come on Silky blades but inverse, the blades are crazy sharp.