I do love this vest, but although I checked my little tension swatch, I never again checked it, so the vest is not as wide as it ought to be and way shorter than I should have ever imagined would be ok. And the thing is... I knew! I just ignored myself, as usual. Idiot!
So, I slid the needle through a row near the ribbing, cut it off and started knitting the other way, to lengthen it. It'll be fine. Under the arms I'll add a little wedge, for extra ease. THEN, I'll write it all down and have a template for What To Do Next Time!