2ND UPDATE
Thanks FFLINCHER I plan to order the paint pen, I think it will work just fine for my application. I wanted to update this thread since having converted two 7.62 Saigas to accept standard AK Mags. I realized how useful a standard flat file is in removing excess material and I now recommend that anyone having issues with a tight fitting dustcover first use a flat file. My air drill worked just fine, but a flat file is even more forgiving and is a cheap alternative. I paid about 5 bucks for mine at my local hardware store. It worked great for shaving off material on my mag catch a