“Can I buy more 'rubber nibs' that balance the stove top grates and middle griddle grates? Continue to lose them when cleaning. On the under side of the 3 stove-top grates and on the under side of the interchangeable middle griddle there are small black rubber-like or synthetic 'nibs' that balance the grates (they are usually found under each corner) and also they serve to cushion the grate from scratching the surface with metal on metal contact. Can I buy 1/2 dozen of these rubber nibs for spare parts? It seems I lose these routinely when cleaning. The result feels like a table that wobbles and needs a match book under one leg to balance it. My grates are wobbling! Help.”