1937 Kellogg's Pep Stamps
 

I know that these stamps were issued in four stamp panels with perforations between the stamps so that they could be separated and put in an album. I know that SGC grades complete panels (there are several on eBay). Does anyone know whether SGC will grade/slab individual stamps? If so, will SGC assign a numerical grade or will it be an "A" designation?

Thanks for your help!