Those are like boat anchors compared to my hotrodded Weimann 500:

Almost stock except for an Italian-made Ti centerbolt. I forget who made it, there were at least 3-4 brands of aftermarket Ti centerbolts, with the central part that holds the spring made of aluminum.
I might make a spring out of titanium too, to shave another couple grams. Not too difficult, can be made of 6/4 welding wire. Jim Merz made some for his amazing weight-weenie Exxon Graftek.
Mark B