This string pack was not manufactured by Parker until about the 1980s. Instead, this string pack was made and sold by the "National Yo-Yo and Bo-Lo Co. Ltd., Toronto - Montreal". Note that it is English-only packaging, not bilingual French and English.
"Mr. Yo-Yo says: 'These are the strings used by Uncle Al Gallo The World's Yo-Yo Champion'."
Identical to the "2 strings for 15 cents" pack and the "2 strings" pack both made by the same company but released at different times.