I never polished the feed ramp on my FALs. But I have tweaked the feed lips in some of my mags. I just used a pair of pliers and some dummy rounds I made. I think there are 3 things you can do:
1. Polish feed ramp.
2. Look at the wings on the receiver inside the magazine well. If you look from underneath, you will see two wings (one on each side) that keeps the magazine from going all the way in. I have heard that these wings may not have the same thickness. In your case, the right wing may be a little thicker, hence causing the magazine to sit a little lower on the right side. If you can slowly and carefully polish/remove some material under the right wing, it may help the mag to sit a little higher.
3. Look at the magazine feed lips. I have like new mags from DSA that will not feed from the right side. Upon closer inspection, the feed lip on the right is pushed down a bit. With a pair of pliers I just raise the lip carefully, a little at a time. Now the mag feeds reliably.
Hey, do you know that you can buy slightly rusted FAL mags from Tapco for $2 each ?? Interested? Let me know before you place an order. Maybe we can combine our orders to save the shipping. 10 mags for $20?? Cant beat that with a stick.
Are you going to FL this weekend?