I am unable to determine how 'deep' the bushing is inserted into the 3cm maple
wood.... it does not go all the way through, and, unlike many 'modern' bushing inserts
there is no screwdriver 'slot'. I may have to resort to using that stuff (gad it's terrible
getting old.. my memory fails me at the most awkward moments) my mechanic son
uses to make sure bolts stay in place. If I 'glue' a 1/4" bolt in, I may be able to extract
the bushing without too much damage, clean it, and re-insert using an epoxy glue.
I might feel better if I can get the original to remain in its proper place rather than
using the rather rough-looking inserts available (and can be ugly, because they are
usually hidden from sight).

....but, I'm still open to other suggestions