The older rods used a alphabetic system of line and rod weight. IE HCH which denotes a double taper line, front and rear tapered to size H and body is C. A GBF is a weight fwd bass taper. A level line would be a single letter.
An "A" line would be heaviest. As near as I can remender, a "C" was about a 6 wt. The rod should be marked with a single letter for the line weight.
The only problem with this system was that there was no standard for what a letter meant. It was up to the manafacturer. The American Fishing Tackle Manafacturing Association (AFTMA) adopted the present labeling system which is based on the weight of the first 30 ft of the line, thereby standardizing the labeling. Unfortunatly, some manafactures are playing games with the standard now. I owned two Wonder rods. A 9' "B" and a 7'"C" Presidential which thought was the ultimate! I'd guess that your rod is a "B" which should be on the label, a 7 or 8 wt.