Interesting unusual find on a 1930s fretboard...

[Kerry Krishna]

 I have never seen anything like this before and thought I would post it here for your perusal.  I have had this axe for almost two months, and ,though I know that the fretboard had been worked on sometime in the past, did not look closely enough, because the  guitar played just fine. All of the frets have been taken off the fretboard, and some kinda dark brown glue used to raise the frets up off the board to about half again as high. The following photos were done on manual setting on my new 1k Canon, and I just had my first lesson with that setting this last weekend. You can (clearly?) see the diamonds of the fret tang through the glue under the frets. ... So have any of you seen or heard of this before. 

[Kerry Krishna]

Tim, , you are right. Two bolts would be better. There would not be enough wood at the top sides of the heal to put the bolts into safely, and I so like the idea of hex head bolts too.