Can Anyone Identify These Buckets?

They are definitely not out of a Ford Torino. They used the same seats as the Mustangs. AMC and Jeep CJ as well as Mopars used the same seats like you show in the picture. 1970 hinge covers were a stand alones with the cover not attached to the back hard cover while 1971-72 were part (attached) of the back cover. The 1970 was prone to breaking off so the 1971 and later were 'improved' version. In 1973 they went to a 'soft' upholstered back that was part of the seat cover top and did away with the hard shelled back. The one pictured would look correct for your Duster unless you're building a numbers matching original show car. Mopar used these same seats in all A, B, E (not familiar with C's but I'm sure they used them) bodied cars starting in 1970.
If you could locate A-body seat brackets then its a bolt-in. Just drill two new holes on the inside tracks. You will have to re-enforce the floor on the inner mounts with sheet metal. I've seen these pieces for sale on E-bay. The factory just tack welded them in. Good luck on the seat brackets since not too many A-bodies came with bucket seats. They may be hard to locate as well as pricey.