On Wednesday, 13 February 2019 16:02:48 UTC, Murmansk wrote:
I'll probably have to make the chute out of MDF but can anyone
suggest a suitable pre-made chute material?

50 or 60 x 100 is a standard PVC electrical trunking size.

https://www.cef.co.uk/catalogue/prod...hite-3m-length

65 x 65 mm is square guttering downpipe

Is this for prostitutes to hand over their clients' cash discreetly? ;-)

Owain