Old painter broke leg on short, short fact-finding mission (2,5)
I believe the answer is:
el greco
'old painter' is the definition.
'el greco' can be an answer for 'painter' (thesaurus). I am unsure of the 'old' bit.
'broke leg on short short fact-finding mission' is the wordplay.
'broke' is an anagram indicator.
'on' becomes 're' ('on' can be mean 'with reference to').
'short short fact-finding mission' becomes 'co' (I can't justify this - if you can you should believe this answer much more).
'leg' with letters rearranged gives 'elg'.
'elg'+'re'+'co'='EL GRECO'
Can you help me to learn more?
(Other definitions for el greco that I've seen before include "Spanish painter born 1541 in Crete" , "He painted" , "Spanish artist born in Crete" , "Greek born Spanish painter" , "Sixteenth to seventeenth century Greek-born Spanish painter" .)