Steve: From what I can see, you're sinew job isn't too bad. To me it looks like you used too much hide glue and maybe tried to fill in the gaps with hide glue, also. My first few sinew jobs, I did the same and got the cracks in the glue like you have. It really doesn't hurt anything. Just makes a lot of noise and scares the bejesus outta ya.
You may be able to "wipe" some of the excess hide glue off with a warm water soaked rag. If there's a finish on it, scrape it off first. It will take a little time. Its kinda like getting to the Tootsie Roll in the center of a Tootsie Pop. It'll take a lot of licks but you'll eventually get to it.
Good Luck!