Sorry, I've been too busy to follow lately but if you want to know a little trick to reduce friction between the leaves cut some 14 or 16 gauge galvanized sheet metal shims 2 1/2 wide x about 5 or 6" long with a 3/8" hole in the middle. Put one between each leaf with the center pin passing through. Combined with the pads at the ends of each leaf there will be an gap
over the length of each leaf so they won't rub against each other during flex. Parabolic springs use this idea. It's one of their claims to fame