Yeah NLG were an option. In our fleet we used to have more than ten aircraft equipped with NLG but I never heared of a replacement because they simply were not used. It's long ago but
AFAIK the pedals had to be deployed to their maximum to activate them. (was there also a speed limit for them, don't remember?) There is very good reason for that. Everybody who has ever ridden a motorbike knows the forces up front during braking. So on the 727 nose gear strut the torque had to be limited not to overstress the strut. An option to get some better numbers on the performance charts like the option of rockets for engine failure on high elevation airports like La Paz.