In any case, since the photo gives it away, I’ll finish the story.
It is a Duracraft ProYo.
From the slightly outdated Museum of Yo-Yo History page about Playmaxx:
The ProYo was developed and patented in (1974). Playmaxx was started in 1976 by Donald F. Duncan, Jr. The original name was “Duncraft”. This name existed for about 6 months and was changed to “Duracraft” at the request of the “Duncan YoYo Co.” as they felt it was too close to their name/trademark. In 1988, Duracraft was changed to Playmaxx as it remains today. The original ProYo was produced until October 1996 when it was replaced by the ProYo II. The ProYo is considered, by aficionados, to be the father of most of the modern yo-yos. It is the most copied high tech yo-yo on the market today. The main features of this yoyo were the central spool that set the parallelism of the two side members and the undercuts on the side members that allowed the use of advertising side caps. This was also an early example of the use of rim weighted design in a plastic yoyo.
Another significant feature was the shape. This “modern” shape is what has made it the father of the modern yo-yo.
The original Duncraft ProYo as produced in 1976. This was produced unchanged except for the name until 1996.
All three of the acknowledged world records for yo-yos with fixed axles as listed by the American Yo-Yo Association (AYYA) are held by the Original ProYo by Playmaxx.
Longest spinner - to extinction : 51 seconds - Original ProYo
Fastest spinner : 11,400 RPM - Original ProYo
Around the Worlds : 26 - Original ProYo
It is a super fun fixed axle throw. The rim weighting and super skinny axle make it both smooth and long spinning. However, it’s major weakness was that the the axle design was extremely fragile. Over tightening or a hard smack on the ground could crack and ruin it. The original ProYo was also available in a non take-apart version with a brass axle and in fact the brass axle was included with the take-apart version, though I don’t know anyone who ever used it.
I bought this one in the early 90’s from National Grand Master and 1992 World Yo Yo Champ Dale Oliver when he was still a demonstrator for Duracraft and lived in Seattle (shortly thereafter he would go on to found his own yoyo company, Spintastics). I had called up Duracraft and ended up talking to Donald Duncan Jr on the phone trying to find out where to buy one and he directed me to Dale. Dale taught me Braintwister that same day which blew my mind as I’d never known such tricks existed.