No, I'm not trying to locate the Rizzas - I know full well who they are. Michelangelo is (99% sure) my great-grandfather but Maria is not my great-grandmother. What I'm trying to do is get as close as I possibly can to the date of Michelangelo's first appearance in Berwick (not necessarily as a resident, but maybe as someone checking the area out for business opportunities. An awful lot of Glaswegian Italian ice cream makers did the same thing at about the same time). I think it would have been some time in 1890 and nothing I've seen so far says that can't be correct (or incorrect, if the truth be told). On the other hand, this thread is making it look like I'm not going to get any closer.
I've been labouring under what is now clearly a misapprehension - that he immediately set up one or both of the ice cream shops we can see in 1894. Of course, he didn't necessarily do any such thing. But all he actually has to be doing is getting off the Leith-Berwick ferry fairly often, because that's how my otherwise-attached great-grandmother knew when he was in town.
And, as has been pointed out, if he's staying at a pub or has a rented room, he would probably still register for the census at his Glasgow address - which is what he did. So, if anyone has a guest book for the Miners Arms at Tweedmouth, it could be very handy indeed. But miracles tend not to happen

Mike