I've owned several of the different nylon rifles but never had the lever. Its crazy what even the 66 mohawk brown will bring in pristine shape to the right person. I've had a couple of the seneca green 66 that were in really bad shape but still sold for what i consider high. As far as your 76, the sky is the limit at auction!
Good luck with it, let me know if you list it on GB, I'd like to watch it go!