It has been done
I did it to a Maadi a few years back. I tried a dremel and was very careful to not remove a lot of metal at a time. Try fitting the mag many times before just grinding away, but the gun will work if you do it right... I remember having considerable feeding issues and much frusration. Cussing was included, as were many hours of zipping away. My Maadi had the magwell dimples, so I used them as a rough guesstimate of where to go. Entirely hand fitted. I'd say just sell it and use the proceeds for a Wasr-10. Did that back in 2000, one of my first "custom jobs" at the age of 20 my friend still has it. Good luck with it if you try it and you can PM me or email if you have any questions. Regards.. Andy