Re: Jetzt

>newaere/niwa:ri = "nicht waere" = "would not be"?

I'd rather say: "if it weren't (for); had it not been."

>How does that meaning evolve into "only, merely, just"?

Even in today's German it is transparent: "wenn das nicht wäre" with
the meaning "es sei denn". Even in today's German the meaning "but,
yet" is rendered by "nur". A highly frequent occurrence, both in
Hochdeutsch and dialects.

George