I thought about contacting Diveney but he's so busy I hate to bother him with questions about cues he doesn't make, and he does make some damn nice cues. :)
If I had to guess I'd say it was probably made by a local guy and sold at an old time drug store/general store in it's time.
As for the Valley cue the dude is selling I could see not knowing I shot the person a message the E-bay seller said he asked another E-bay seller that always has vintage Brunswick cues listed and that's where he got the original information about it being a Brunswick or Sutra cause the guy was a dealer ,for Brunswick ,Richcue and many others in that era. Hell I didn't even know Valley made 2-piece cues untill you posted on this thread.
I grew up in the Adam/Steve Mizerak Series/Huebler/McDermott/Meucci/Mali and so on cue height in the Early 1980's when demand became huge again for quality cues. As you know it comes and goes.
The case look's authentic. The only ones I've ever seen had crowns on them so I'm not sure how they marked them prior to the crown stamp.
The problem is there's a lot of misinformation on the internet and everyone is an Expert. I just research something and if I draw dead I usually pass because rare stuff pops up. Every once in a while someone does have a rare piece and they don't know it. I look for those and if it goes to high I pass on it.
If you think about it, Adam cue alone had so many models and cues there are a lot that aren't easy to Identify. They were meeting a demand. The same with Kao/Kao corp. Back then they had like 8 lines of brands basically all the same inlay just a different name and they're still doing it today.
These cues come and go on E-bay until they start falling apart, then its time for a name change. I never frown on anyone if they simply don't know what they have. I, much like you, will steer them in the right if they want to listen. Some sellers don't want to hear the truth. Everything is "Vintage" and worth millions on eBay.
Have a good night and let me know if Diveney does indeed get back to you as I still would like the story on Fort Dodge.