The B-52H is the only version still around

and that model was extensively remodeled. The original fuselages for the B52A & B52B were built in the early 1950s (prototypes were built in 1946, but mass production didn't start until later). The last B-52H was built and delivered in 1962.

You want a new bomber? Or more B-2Bs? We still have cruise missiles and ICBMs, as well as nukes on missiles launched from submarines. I haven't read anything about why we need more bombers, but maybe I missed it?

Link: http://airman.dodlive.mil/2018/04/16/b-52h-stratofortress/