I AM very cranky... and beginning to get old.
The whole nose end of the lockplate could be higher. Bending it up helps, but still the spring is angled up. Or, if the frizzen "toe" area were lower and the pivot screw mounted lower, it would have a similar effect of straightening out the spring. The frizzen spring really has to reach up to get to the frizzen.
Bending the lockplate is easy. Clamp the front end of it in a vise and whack it. Of course, there's some clean up, but it's surprisingly easy to bend.
I wish I could weld, and I'd just add some metal to the top front end and I could shape it as I would like... but I have tried and I have tried, but never been successful at welding.
I have an old one on a gun I did many years ago. I got it from "R&R", during a period when Chambers apparently was not making them themselves. I do like the older tumbler and sear, it seems much more suitable for this size of a lock. I also have an old set of as-cast tumbler/sear/bridle that I am jealously hoarding....