My OP did state the clean gun was put in a slip, the reason for that is that the gun only just goes in the cabinet and can easily scratch the better guns in the cabinet, hence it goes in a dry light none water proof breathable slip, unfortunately the old dog relieved himself next to it just before I returned it to the cabinet and it soaked a bit up. Luckily the smell alerted me when I next opened up.
Thanks to your advice I ordered some 0000 grade wire wool and following the advice used some Tetra gun cleaner (just what was to hand) and working round the barrel easily cleaned off the rust and a fleck of paint off a choke. I am very pleased with the results and the bluing is not affected. Thanks for the help its much appreciated. You gave me the confidence and knowledge to sort it out.