B-17's and PBY's were used in the search and rescue role.
If we "stretch" the meaning of operational,we can add the P-80/F-80 Shooting Star,as well.2 of the earliest pre-production models flew a few reconnaissance missions in Italy in April/May 1945.
The British used Fireflies and Meteor jets,however not versions of the 2nd WW
Weren't the TBF/TBM Avenger used in one function or other in Korea?
B-25 Mitchells were used on liaison duties from Japan.