Autolite plugs likely have that tip as well, I used them on Fords and the ones that tips came off of.
The wire electrodes only have the tips when the plugs are intended for waste spark ignition systems as 2 of the 4 plugs (or 3 of 6 if a six cylinder) fire backwards on those. Like I said the major erosion occurs on the tip the spark is jumping AWAY from. Separate coils like Nissan have now do not need the welded on tip on the wire side at all, they fire in one direction only, from the center to the wire.
Platinum plugs use that doubled tip both ends too if they are 'double' platinum plugs, and why they are called that. Platinum plugs WILL wear faster than iridium and why iridium were designed, the first truly 100K plug under optimum circumstances. Or so you hope.