awesome!
you know, as far as switching out different spring gages, instead, you could add a bigger washer, (maybe a penny with a hole drilled in it) to the rear tab. that would shorten the spring, stiffening it up.
They also make #8 washers that have a 1/2" dia. instead of a 3/8", which would also stiffen it up.
-but it seems you got it to do what you wanted now with the spring length where it is at