Himself logged on and had a look at the pictures and sent me a message saying: "Very nice, but aren't they a bit on the large side?"
I grabbed my research pictures of the house in question and started counting slates.
Dammit, he was right! (He usually is...)
The prospect of ripping off and relaying all the slates - only even more of them - didn't immediately appeal.
So out of curiosity I delved in my drawer and pulled out the remains of some sheets of Wills 4mm roofing slates I had left over. (I erroneously wrote last week that these were made by Slaters) and they were indeed much smaller than my paper ones and a much better match, in terms of the number of slates on each section of the roof.
You can compare below.
Fortunately I had just the right amount of sheet, in the right sizes, to cut some replacement roof sections.
So, a week on, the house is back where it was.
Oh well, some you win....