It was either Eric or Marie who wrote on the bottoms of things.
Said did not sign anything, a member here, Wolfie, got that information from Said himself.
The writing on the bottom of this is Marie's. Eric Dobson's writing was more rounded.
You have a round polished pontil mark there, that too is an early-ish feature, it was not continued, I don't believe, after Boffo left, but is still very unusual.
So is the vertical stripe design of Ming on a cylinder. You find it on globes, but not often on anything else.

Mdina, written by MH is very unusual, possibly about as unsual as a full signature.
I've got three of those, but about 15 signed.
I don't go looking for signed pieces and normally avoid them because of inflated price.
I'm not interested in scribbles on the bottom of pieces. They don't add anything artistically and cost far too much.

I do not know if MH made every piece he did write on.
I tend to look at the glass to decide if I think he made it, and I do think that the pieces I have with this mark are made by him, they're subtle and have comet like trails of iridesence but I have no way of confirming that he did make them.
Boffo could produce comet-like trails too.
To bring out a tiny signature for photography, try rubbing a little talcum powder over it with your thumb, to bring up the mark.
