Light work made of royal revolution once previously (3,8)
I believe the answer is:
hms pinafore
'light work' is the definition.
(I've seen this before)
'royal revolution once previously' is the wordplay.
I cannot quite understand how this works, but
'royal' could be 'hm' (His or Her Majesty) and 'hm' is found in the answer.
'revolution' could be 'spin' (spin is a kind of revolution) and 'spin' is located in the answer.
'previously' could be 'afore' (I've seen this in another clue) and 'afore' is located in the answer.
No letters remain.
This explanation may well be incorrect...
'made of' is the link.
Can you help me to learn more?
(Other definitions for hms pinafore that I've seen before include "Light work" , "ship?" , "G & S' alternative for 'The Lass That Loved a Sailor'" .)