Baby Bat Kites
(Austin, TX, U.S.A.)
At https://www.my-best-kite.com/baby-bat-kite.html, you said you thought the spars on Baby Bat kites had always been plastic. I remember pretty well that at least for a while they came with a wooden dowel when I was pretty young. I was born in 1967.
I'm putting this through as a 'Question / Answer' since you didn't leave your email address for me to contact you. Never mind, thanks for the correction regarding the earliest Baby Bat kites! I love it when people help to improve the quality of information on this website.
The relevant page has been updated, and will soon be re-listed under the what's new link over there on the left, near the top.