the issues with the knees is any easy fix ! you just have to crack them open before you try to transform him and either dremel the hole , or sand the peg down .
what happened was that the thigh section went from being molded plastic to painted plastic which included the peg, unfortunately the peg/hole wasn't designed to have enough tolerance to support the extra thickness created by the paint

yeah i'll be messaging the mp09b seller and requesting him to cancel my auction