'76 factory sunroof with a factory 360 I haven't ever seen one like that. Not a lot of '76 Dusters around in general. They were throw away cars, ran hard, rusted out, junked, wrecked, not here anymore. Chrome bumpers, rally wheels or dog dish hub caps, get it running good, detail it up, make it as stock appearing as possible I think it would be a lot more appealing.
Wasn't that long ago '73 and up cars no one wanted. That is changing because the values of the earlier cars are getting out of reach for a lot of people now. I think the later cars will ride the coat tails of the earlier cars over time. I would not be in any hurry to get rid of it if I were you. And if you do sell its near guaranteed your will ever be able to get another one like it ever again. Join the ranks of "I use to have a" and "I wish I would have never sold" crowd. Once its gone its gone you are not going to be able to get one like that ever again. You won't realize what you have until after its gone.