Unclued lights, singly or correctly paired, are of a kind, as given in Chambers. Ignore one apostrophe.
 

Across

5    Maiden admitting born overseas originally, not in Danish city (6)
11    Author’s note on leader of band (6)
13    Sort of thinking muscle real troublesome (7)
15    Old royal servant, one that looks to captivate women (5)
16    Tragic heroine misses artist, not in office yet (5)
17    Tropical veg regularly feed herbivores (6)
18    A rector ruined can’t function (6)
21    One taken in by eccentric vagrant (5)
22    Shelf with enough strength after soak (7)
28    Wild about education, like the US government? (7)
31    No time for reproaches in letters...