What can I expect from lower eyelid grafting? Will it be that noticeable after it heals completely?

If you have a true skin deficiency which is causing your problems then you would most likely need a skin graft.  The cosmetic result will depend on the size of the graft, where the skin comes from and whether or not the graft survives.  You have already had multiple surgeries here which may affect the blood flow.  If you have enough skin on the upper eyelid, this is the best place from which to take the graft as the skin will be the most similar to the lower eyelid skin.  Once the graft has healed you can do some laser to the area to blend in the skin if needed.  At times grafts can look great - but in others, they may appear thick and lumpy.          

Skin grafts can heal almost invisibly but this depends most on the match between the graft and the eyelid skin.  The Closest match is from the upper lid but frequently following an upper lid bleph there is not adequate skin available. No other skin is as thin but the skin right in front of the ear or above your collar bone can also be used. If you have had multiple surgeries it puts you at some risk for poor healing but in general the grafts heal very well. It is your best chance at successful repositioning of your lid so best of luck.