Funny thing about these kits to me is growing up in the 60s and 70s in Colorado most of my kits were Estes but then again they were home town back then.
The only thing I remember Cox for was control line airplanes never even knew they made rockets till I saw them on here

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NAR # 102461 SR
I have orbited the earth with John Glenn, walked on the moon with Neil Armstrong, landed on Mars, seen Jupiter and Saturn and explored the realm of deep space all thanks to Model rocketry.
God Bless America and The United States Marine Corps