How many CURRENT owners of real '74 360 Duster 4 speed cars on here?

I'm gonna be having a buddy bring his 74 Duster 360 4sp with pistol grip shifter into my garage to get it running here in the next little while. It's been parked in a garage for the last 20 years. No rust. Blue velvet and black vinyl interior in very nice shape.
Is this the kind of car that should be kept 100% factory? I understand that there's not a lot of them around but would it be worth a lot more if it was kept stock?
Thanks