Oh yes I can see it's Jerome so it was a logo of sorts.
Looking at those links, it seems this postcard predates Jerome taking over Gales studios, as this card doesn't have 'branches everywhere' which was the message on Gales advertising.
There is also no violet ink date stamp, which absence might indicate something.
I shall contact the website owners of the links posted and send them the pic to see if they can narrow down the date. Hopefully it was when Jerome was only in a few places. If only London, Liverpool and Manchester, then it's very likely to be the London studio, based on the family history.
Thanks so much everyone for helping out.