Thanks everyone! Vodka, we 69 Imp folks need to keep in close touch, huh? So anyway, my car was built early in the model run, one of the first in fact, being built the first week of September, 1968. And as sometimes happens on the first few cars of a new design, my fender signals had NO crappy little nuts - not on either side. What it had was sticky black tar gobbed on each of the thin spindles that fit into the two holes. I used my fingernails blindly to pull some of it away, took a hard plastic trim removal tool, gently pried front and back, side to side, on each signal. Voila! They popped right off. Love Mopars and early run vehicles. 'Hey Fred, what kinda nut you figger goes here? Well hell, give me some of that black goo and well send her on down the line."
Thanks again everyone.