Tony:
The Pila 3.7 V LA comes with only an anode spring, not the larger outer cathode spring of the SF Px, Nx, and MNx LA's.
I made mine work in a 6P by using a loose, cut-off Cathode spring from a dead P61 LA, but I couldn't arrange for good contact with a 6P head on an e2C adapter and e2 body.