Davecam48
Poster Extraordinaire
Sorry ...........I missed the pix of the bolt heads to the front of the base just behind the castors. For some reason I only saw the two bolt heads at the back. Creeping senility is not good!!!! If it was my problem I'd probably drill 4 hole in the floor to accommodate the bolt heads during buffing, or 10 bricks on the base, or make the wife sit on it while it's going. 
DC
DC