The font I used to clone this one from ended up looking nothing like Copperplate gothic, so I thought why not go the whole hog and create a lower case for it?

I was about half way through when I began to suspect this one is very like a Fontstruction that somebody else has already done? Maybe it's me, ha ha.

I don't know any more, my head's in a spin.

Not quite. I'm not able to resolve some of the jots and tittles. The right-side serifs on some of the lower case don't quite match because it's half a brick leaner than the caps in the width of the downstrokes. Not much I can do about the l/c i and j which look a little gross, which means all the punctuation is going to look too heavy.

Damn, now I've gone too far the other way in my drive to be efficient. I've got a three-bedroom house, maybe it should have been a four...