Lucky man! I would suggest using round dowels instead of toothpicks. On that size of plane your firewall should be thick enough to take 1/8th size dowels. That would be much stronger I would think. Just be sure to drill straight and centered. Other than that, I'd say don't skimp on the epoxy. I you can, go around all four sides on the backside of the firewall with your triangle stock. Some planes just have it on either side. I say if it helps... add a little extra. Another thing I did on my Giant Stinger was (before drilling and glueing in those dowels) go across the front of the firewall with fiberglass. Extend the fiberglass around the sides of the fuse some. Not too much that the cowel won't cover it though. After that is set and finished to your satisfaction, then drill and epoxy in the dowels. Maybe this is a bit much, but I tend to overdo these types of things. I guess I'm just paranoid that way!