Surprisingly, the process of return (re-evacuation) is not that well studied. I could find a couple of dissertations (mostly focussed on people migration than industries per se, but they are closely linked), all in Russian. My brief take is this:
There was a small wave of re-evacuation from as early as December 1941, right after the Battle of Moscow, primarily for the Moscow industries. These factories were generally re-established.
An overwhelming majority of factories remained in the East (primarily in the Urals) after the war. Some data for the Chelyabinsk region (southern Urals): 178 facilites were evacuated there, of them 155 heavy industries. By 1946, only 10 were re-evacuated.
Most of the "original" facilities were also restored, and were initially supplied (starting from 1943) with the "excess" equipment that couldn't be deployed at the relocated facilities. This was rather in the form of "economic assistance" rather than official re-deployment.
Most evacuated people were eager to get back. Authorities tried to prevent it, even after 1945, but the majority returned, by hook or by crook, leaving the factories to the (generally less educated) local workforce (as well as to the migrants from the Central Asian republics and prisoners). Still, even by 1948, more than 65000 evacuated people remained in the Urals alone and were unable to move.
 Marina Potyomkina, Processes of evacuation and re-evacuation, and the evacuated population in the Urals in 1941-1948, Doctor dissertation, 2004.
 Vadim Shuvalov, Evacuation was hard, but return was harder (interview with Marina Potyomkina).
 Artyom Churikov, Management, manufacturing and social problems of evacuation and re-evacuation of heavy industries in Chelyabinsk Oblast (1941-1946), Ph.D thesis, 2011, synopsis.