Salvage run on 2 September, say (7)
I believe the answer is:
reclaim
'salvage run' is the definition.
'reclaim' can be an answer for 'salvage' (I've seen this before). I am not certain of the 'run' bit.
'on 2 september say' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'l september say' becomes 'claim' (I can't justify this - if you can you should give a lot more credence to this answer).
're'+'claim'='RECLAIM'
Can you help me to learn more?
(Other definitions for reclaim that I've seen before include "Seek or get back" , "From sea, rescue" , "Get back (airline baggage)" , "Get back (eg from the sea)" , "recovery like this" .)