...to this I added strips of zinc metal, from the outside casing of a battery which I polished shiny
Sorry to butt in, but I had to ask. You said the outside casing, but did you mean the inner can?
The reason I ask is, in both alkaline and carbon-zinc batteries, the outer cans are almost always a sheet of nickel-plated steel. Some are zinc plated, but the base metal is still steel. You can verify that with any old magnet.
Now, in carbon-zinc batteries, there's a separate solid zinc can inside that steel outer can, but those aren't sheet zinc, rather, they're a disc that's formed into a can by a press. So, those would be pretty darn hard to cut into strips without a good pair of nippers.
Just wanted to clarify for my own curiosity, and also in case you did in fact try this reaction with the outer casing. I'm guessing that would form whatever compounds HCl + steel creates, but not the ZnCl2 you want