Mystery Tool - Mahogany Float With Metal Piece?

[melmurdock]

This float is mahognay and marked with the old Ace Hardware airplane logo.

I'm baffled about the metal piece on the bottom.

I've floated cement and layed tile for 35 years (as a profession) and have never seen this float. It doesn't look modified but I guess it's possible.

Anyone? What purpose does the metal piece serve?

Any input would be appreciated. Already researched Ebay and Google to death.

Thank you!

[milestoneks]

Obviously converted from what was originally a standard float. Maybe held a specific piece in place while doing intricate work? That metal piece maybe held another piece/tool?