I got a can if Spaulding tennis balls for $1 at a garage sale and saw a half dozen or so at a play it one more time (again) shop. Can't remember how much it was going for.
You should open a can! Does it need a key to open it like a can of corned beef or does it have a similar top to the cans of today?
Married into a tennis fam-trying2keep up after4knee surgeries. I almost have more racquets than my wife and in-laws (don't tell the wife)