Originally Posted by
Jim Kukula
I've read that the usual cause of this squeaking is metal-on-metal. A drop of lube up by the nose where there are lots of metal parts that can rub will probably do it. Or maybe by the springs - not the springs themselves, but the bolts that hold them or anywhere else metal can rub on metal.
Don't get the lube on the leather though. Leather likes beeswax and biological oils but petroleum oil is not so good for it.
My B67 did the same as the O.P, I assumed it had to be metal-on metal by the sound but no end of tightening & lubing would stop it, in the end it turned out to be leather on metal squeaking solved by what's already been suggested, proofide between the leather/metal contacts.
To the O.P, if it helps Proofide ingredients are (don't know %'s)-
Tallow- (animal fat)
Cod oil
Vegetable oil
Paraffin wax
Beeswax
Citronella oil
I guess shoe "dubbin" or horse tack Saddle soap in small quantities won't do any harm either.