Thank you, Karim, Ras and Bill, your comments are much appreciated, as ever.
With the original photos I took some of the custom ladder and the original, but I missed the fact that the camera had focused between the two ladders, so here are some taken indoors this morning.
The custom ladder, on the left in the first picture, is only slightly longer than one length of the original (on the right)right, but that bit extra length is useful for access and, more important, the custom ladder is much easier when it comes to manoeuvring it in narrow streets.