Check through the Double Gun photo archive for pictures. Either a straight grip with re-checkering, or a grip cap, not a combination of the two patterns like they've put on that stock.

For me, it's a poor looking stock design and done that way to cut costs - no hand work at all, all fast machine work.

Balancing out the rifle with some lead in the butt might help, but do not screw up the balance. Depends on what you want, quick handling, balancing at the barrel pivot, or slight muzzle heaviness for more accurate offhand shooting.