I saved the pics and put them up on my big high res monitor. I don't think it's Dacron. It looks like it might be natural fibers.
Dacron, for those that might not know (I know you know) is a brand of polyester. It is used in many things, including textiles and fishing line. Cortland did and still does sell Dacron fishing line (at least they still did the last time I looked). There are have been numerous brands of Dacron fishing line, including green spec.
Nylon is another can of worms. It's a different synthetic with different properties and feel. It has also been used on many pool cues.
I have seen the common synthetic fishing lines used, and also threads meant for the textile industry. I have an ebony Titlist converted by Ricco Cervantes that is wrapped with nylon thread.
As for Dacron, GB did use it on some cues, I have pictures of one in my wraps folder, I think I grabbed that pic here on AZB years ago.
The synthetics don't sand/press/polish like natural fibers.
Generally, people very often confuse the names and materials a lot.