Old Town Kingfisher repair advice

Hi folks. I just picked up an Old Town Kingfisher 14-footer that needs a little work and I could use some advice before digging in. There’s about a 4-inch crack that only appears to penetrate the first layer or two. From what I’ve found online about this canoe, it’s made with Royalex–I’m not too knowledgable about Royalex. The inside of the canoe is a thick weaved material.

  1. What can I use to add a thin coat over the inside of the canoe? I’m worried about my kids getting little shards of whatever this material is.

  2. Was the Kingfisher always/only made from Royalex? I want to make sure I’m dealing with the right material before repairing the outer damage.