Am looking For Clamp Spring ,old B&L Custom Mount or Kunarsky Bros.

[NB Rifles]

I put a add in the Exchange section but thought I would post here incase someone knows where i can find the piece. It's OAL looks to be about 3.875" or about 3.625" from the V in the clamp. Would be using it on the Kunarsky Bros 722 mount.
Thanks
B.