I have since bought this glass with a printed flower that looks to use the same process as for the horse, the flower is the same image as printed on the Webb Corbett style weights. I posted photos of this glass on the paperweight topic and Chopin-liszt identified it as by Dema.
http://www.glassmessages.com/index.php/topic,71964.msg400930.html#topLooking at the detail of this flower glass, you can see that each layer is on top of the other, this doesn’t look like it’s been transferred by a rubber stamp as I previously thought as I don’t think you would see the layers so clearly. Also, you can more clearly see the shadow of the grid of the screen used in the printing process.
Looking into Dema, I found this fantastic “Dema” screen printing machine that prints more than one layer directly onto glass (bottle printing shown in the clip):
https://m.youtube.com/watch?v=GazwA13MFJY I think this process was used, especially for the flower.
Some of Dema history here:
https://www.chesterfield.gov.uk/explore-chesterfield/museum/past-exhibitions/touch-of-glass.aspx