Mandy Picture Story Library for Girls was a 68 page monthly comics digest, a spin-off from the girls' comic Mandy. It was one of four such digests published by D.C. Thomson, the others being Bunty Picture Story Library for Girls, Debbie Picture Story Library for Girls and Judy Picture Story Library for Girls.
I have up to #273 titled Dogsbody Debbie - any more after that? The last issue I am sure is #277 titled "Friend from the Future".
Note: some PR issues may have no value. Selected issues in FN, VF or VF/NM may not exist in some titles.