Roller-skating frogs!! - Yes, really...

I just have to share this discovery!  I'm doing some research which involves looking at old pattern books, and came across this in the Thomas Webb archive (deposited with the Dudley Archives at Coseley in the West Midlands).
If I hadn't seen it and photographed it, I'd never have believed it.  Does anyone know if it was ever made?

Image icon SkatingFrogs06.jpg251.52 KB