Here's some pics of a way to make a turret board with home tools.
Tools:
Build an anvil out of a pice of steel (flat bar or bolt). Close to the edge of the anvil, drill a hole to suit turret size but not too big for the turret flange to fit through. Drill it deep enough so the turret fits inside.
Get a common center punch.
1. Drill holes in turret board to fit turret
2. Insert turret into anvil
3. Press board over turret
4. Use Center Punch to flange the turret - 2 light taps
4. Remove punch; finish flattening turret onto the board - 2 light taps.
5. Repeat for all turrets.