"Ate fish over at King's Head - this one?" = haddock. Is there a cryptic element to the 'addoc'?
"Illegally convert three articles abroad" = launder. Hah! Just seen it. Good clue.
"Repairman keeps a snake" = meander.
"Lie on cotton for instance" = fibre. Where do we get the 're'? Would a better clue not be 'lie ABOUT cotton'?