Peter, J.S. Bell does not use any assumptions about QM. Nor do I.
Where is there any assumption about quantum mechanics in the following experimental protocol?
Alice and Bob are in different classrooms and in each classroom there is a black box, called "measuring device A" and "measuring device B" respectively. These two boxes are connected to another black box in another classroom, called "source", through some kind of cables, tunnels, or whatever, so that all three black boxes have means to share any information they like. Alice and Bob's boxes each have two buttons, and two lights. The buttons can be pressed, the lights may or may not flash. The communication channels can be switched on and off.
You are going to provide these boxes and engineer the communication channels between them. I don't mind what you put in them (spinning disks, shuffled packs of cards...) or how you manage the communication. Now comes the experimental protocol.
Initially the communication channels are open.
Now repeat, 10 000 times:
Step 1. The connections are severed.
Step 2. Alice presses the button marked "0" or the button marked "90"; Bob presses the button marked "45" or the button marked "135". After Alice and Bob have each pressed a button, a red or a green light flashes on their box. They record their input and their output.
Step 3. The connections between the three magic black boxes are restored.
Your job to engineer those three boxes and the channels between them so that:
Prob(lights flash same colour | 0, 45)
= Prob(lights flash same colour | 90, 45)
= Prob(lights flash same colour | 90, 135)
= 0.15
Prob(lights flash same colour | 0, 135)
= 0.85
To make life easier for you, I just ask you to write three computer programs with simulate the three magic boxes, to be run on three separate computers sending one another messages by internet (to simulate the communication channels). Fine by me if you just write one computer program but it must be clear that it could be broken into separate pieces as required.
I happen to know for sure that you can't do it. I'm not going to even start to try to explain why. If you want my attention (or the world's attention) you'll have to program it yourself of get someone else to program it for you. If you succeed you'll get the Nobel prize for the first loophole-free experimental violation of Bell's inequality, and moreover you will have totally revolutionarized the whole field of quantum physics, since you'll have shown that quantum entanglement is completely classical.