I'd check out some of the posts for English paper piecing and also have a look for hexagons here on the board. If you can find fabrics that are sort of in keeping with those in the quilt you're probably good to go for replacing the 'holey' hexagons. Definitely a hand sewing labor of love................ I think you can finish up with half-hexagons and then border or bind as usual. Probably way more expert advice coming your way. Good luck!
Hope we get to see a picture.