My brother in-law cut the top half of the peep sight off, more for keeping water drops out of the hole. I would think taking a conical dremel cutter or sanding stone and enlarging the hole(ghost site style) might work. Garand peeps are still abundant I believe. All I have done is installed a Shuster Adjustable Gas plug so I can shoot 180 gr. Partitions with no worries, on mine.
A co-worker has a scout type upper rear hand gaurd with a picatiny rail. A scout scope or red dot would work well.