The appeal of a dying craft perhaps (3)
I believe the answer is:
sos
'the appeal' is the definition.
(I have seen 'urgent appeal' mean 'sos' so perhaps 'appeal' could also mean 'sos')
'of a dying craft perhaps' is the wordplay.
I cannot quite see how this works, but
'of' could be 'o' and 'o' is located in the answer.
'craft' could be 'ss' (prefix in ship names eg SS Great Britain) and 'ss' is found in the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sos that I've seen before include "Morse Code for help" , "Coded distress signal" , "Appeal for help" , "Help with dots and dashes" , "International distress code" .)