Mujitsu and Tairaku's Shakuhachi BBQ

Hello,

I'd like some advice on repairing an old (50-80 yrs) jiari shakuhachi.  It's in very good condition except:

1) The upper section is cracked through.  I bound it, and it has no leaks, but the crack doesn't go together perfectly.  It's offset just a little bit, so the exterior and interior are not perfectly smooth.  Is there any way to correct this?  I wouldn't mind re-binding it, but I don't see how to get the edges perfectly aligned while I'm wrapping it.  Or do you even think it's worthwhile?

2) There's a small chip out of the blowing edge of the utaguchi inlay, where it meets the bamboo.  I wouldn't attempt to replace it myself, and not sure I would want to.  Can anyone recommend a way to patch it?

3) There's a small chip out of the bore in the upper section, at the crack.  What's the best way to repair that?  The interior has a mirror finish, and I don't want to disturb it any more than necessary.

4) The joint was loose, mainly due to the upper section being cracked.  I bound the joint with monofilament and it's pretty tight now.  The only problem is, the ring that covered the joint won't fit over the binding.  It's a black material - plastic?  bakelite? - and cracked when the top section cracked.  Any suggestions about what to do?  Bore out the original ring so it fits?  Make a new one out of ... something?

In general, I want to make the least invasive repairs that will restore the flute to full working condition.

Thanks,
Robert