Lots Of Gear Don't Know How To Use It

That looks close. What you're doing with that Kelvin setting is matching the Kelvin Temperature of the lighting - the same color scale as used in astronomy to describe star temperatures. This image, even if not color-perfect, is so close that adjustment in postprocessing is trivial.

I have clicking away since you said I was close on the WB.
Rmpsrmps, what program did you use to check the whites on my coin flips?
So my reversal ring just arrived. I tried using it on my own but the results were terrible. very dark images and not as magnified as I thought. I obviously have to shoot full manual with this setup, any suggestions? I'll post the attempts if you want, but I don't thik they will help.

So my 50mm lens with macro stack (1x,2x,and 4x) works great with half dollars, good with quarters, but is not close enough for smaller coins. The reversal ring while very inexpensive is very difficult to use.
So to get closer should I buy a old prime 85mm or more or go full monty and get a dedicated macro lens.

Off the top of my head - understanding I lack experience with them - I can't imagine a stack like you're using being insufficient with the smallest of coins. On the contrary, I expected there to be some which you couldn't fit completely into the frame. Have you satisfied yourself that you're at the minimum possible distance from the subject to achieve focus?

If that be the case, experiment with fewer lenses in the stack. They may be limiting the minimum-possible focusing distance themselves. Try each alone, just to see if they allow you to get physically closer. Let's exhaust all possible combinations of the equipment you've got before we start spending more of your money.

Further, Ray will see this bumped the next time he's here, and will almost certainly weigh in with his broader experimental experience.