Noticed on my present game that some of the quarry images are clay pit images rather than quarry images.
https://github.com/jamespetts/simutrans-pak128.britain/blob/master/industry/quarry.png
Quarry (5,4) => (6, 7) are the problematic images.
Thank you for that - I see that this was fixed in the Standard version some years ago: I must have missed this. I have now copied over the fixed graphic, so this should work correctly now.
Thanks James! Confirmed fix in latest nightly build.