I've just looked at my 5 examples of the signature and I don't think this fits in with any of them.
Does the 7 have the bar across it's middle? Sam's do.
Also, this looks terribly like Mdina. It would be an unusual sort of experimental Fish.
It doesn't look like Sam's work.
His signature does vary, but is mostly very sloped.
Sorry to be the bearer of non-Sam tidings, but I'd suggest heading back to Malta for your Id.

But also, wait until you hear what Greg might say. If Greg doesn't agree with me, I would revise my opinion.