Extra for mortgage raised in review of platoon (3-2,4)
I believe the answer is:
top-up loan
'extra for mortgage' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'raised in review of platoon' is the wordplay.
'raised' becomes 'up' (similar in meaning).
'in' is an insertion indicator.
'review of' is an anagram indicator.
'platoon' is an anagram of 'toploan'.
'up' inserted into 'toploan' is 'TOP-UP LOAN'.
Can you help me to learn more?
(Another definition for top-up loan that I've seen is " further advance".)