I've slicked up a 410 from Yildiz for a pard's grand daughter and found it to be a very nice gun for the $$. Not too difficult to work on and very usable once done.
I don't frequent the wire so I'm just now learning of this. So sorry for all you've both been through. Prayers for you and Schoolmarm for continued improvement and complete healing my friend.
The one pc mod features a single pc firing pin that extends through the firing pin extension as well as the bolt eliminating the extra "step" in the travel. Less mass to move so less energy required. On a stock setup the hammer strikes the firing pin extension which then impacts the bolt.(2 pcs between the hammer and the primer.)
It's kinda like taking out the transfer bar and modifying the hammers so the hammer directly strikes the firing pin on a Vaquero.
The extra light can be too light to consistently set off non federal primers. If I remember correctly it is more designed for rifles with the one pc firing pin mod such as the one by Snake Oil George. I have this mod on my rifle and would highly recommend it.