Colt M1917 Mainspring increase pull

[BVZ24]

My Colt M1917 has a replacement main spring sold as for the army special. I have a nicer Colt that retains the original heavy spring, so when I purchased my shooter revolver with an unknown very light yet thicker spring already installed, I replaced it to save the trouble of guessing. It was fine for a few years but now I'm having issues with light strikes in D/A only and narrowed it down to the mainspring.
I want to A increase the pull on my replacement spring or B replace it again with a heavier spring.

Does anyone have tips or tricks for A? Usually people are trying to lighten these springs, not make them heavy.

Does anyone have a good vendor for B that has a spring halfway between army special and original?

I'm also looking for a recommendation on a good vendor for a set of new service style polymer grips. Some that won't overhang and won't shift when firing.

Thanks ahead of time.