golf bab bottom placement?

I'd be tempted to say use WBP (Water and Boilproof Ply)

X
August 2015

Make a cardboard template - use it to cut out a piece of plywood - stain the wood black & varnish it.

Make holes in the plywood base and matching holes around the bottom of the bag. Use soft Garden Wire through the holes and twist it up neatly.

Presto! - A restored bag...

Alternatively buy another bag.

Good Luck...
August 2015