there are varying degrees of chrysls,,,, just because you have some minor ones does not mean the bow is gone,, I am shooting a 20 year old black locust bow,, that had some chrysls when when I got in a hurry tillering,, I didnt remove wood from that spot and tillered the bow more evenly and it is still shooting great no set 20 years later( with no increase in damage),, I shot this bow alot through a couple of tournament seasons,,, it really depends on how bad they are,, and if you can even the tiller to take stress off that part of the bow,, I have a friend that damaged his first bow and it chrysled,, we evened the tiller and still shooting fine,,years later,,,, that being said I am sure some bows have been damaged beyond repair,,, if the bow is slightly overbuilt you have more of a chance,, if the bow is stressed to the max,, then chances of recovery are less,,, that is why when first building a bow ,, an overbuilt design gives you a better chance of success,,,, as far as patching I am not an expert on that,, but if you can make that part of the bow stiffer,, and reduce stress to the belly there,, it should help in some minor cases,,,,,