I awarded an unusual selection of historic items (10)
I believe the answer is:
edwardiana
'selection of historic items' is the definition.
(items from the Edwardian era)
'i awarded an unusual' is the wordplay.
'unusual' is an anagram indicator.
'i'+'awarded'+'an'='iawardedan'
'iawardedan' is an anagram of 'EDWARDIANA'.
(Other definitions for edwardiana that I've seen before include "century-old articles" , "set of old articles" , "period items" , "hundred-year-old items?" .)