Old Nicaraguan guerrilla group’s smuggled goods (10)
I believe the answer is:
contraband
'smuggled goods' is the definition.
(I've seen this before)
'old nicaraguan guerrilla group's' is the wordplay.
'old nicaraguan guerrilla' becomes 'contra' (term for a Nicaraguan counter-revolutionary).
'group' becomes 'band' (I've seen this before).
'contra'+'band'='CONTRABAND'
(Other definitions for contraband that I've seen before include "illegal trade" , "loot" , "Smuggled goods" , "Illegally brought in" .)