As it sits, it is probably a $15k car, +/- a grand, depending on the state of the paint under that plasticoat.
It sounds like you have done a fair bit of reconditioning work, which is a positive. SCs in interesting colors are usually a significant value bump. Paint to sample Turquoise(?) may test that theory. Is the paint tag still on the car, showing the number?
Running, shifting, driving, and stopping -- with no rust -- and registered street legal is significant when valuing a project car. And this is still very much a project for someone.
I'm not an aftermarket wheel guy (on any car) -- but I agree the Ronals look nice, and fit the color scheme reasonably well. They add zero to the value of the car, though, and if you DO go to sell it, you should put the factory wheels back on, and sell the Ronals separately. Otherwise, you will basically be throwing them in for free on the deal. Selling off the Fuchs from the original car would be a sin.
It looks like the interior was brown. I dig brown interiors, but they are pretty hard to source second-hand. On the plus side, there is also a low demand for them, so perusing old classified ads might find some unsold pieces -- even if they are many months old.
You said the car is not for sale at the moment, and are concerned about putting money into it.
You need to think about what your true goals for this are. If you don't think you will keep it for the long term, I recommend you minimize any further customization, and browse the "for sale" classified to find the used parts to get the interior in a better state. A carpet set, new heater hoses (which should cost very little), and stock seats will go a LONG way toward increasing the value of the car. Core seats are readily available, and vinyl recovering is not that costly.
Even respraying the hood and light rings can be done relatively cheaply if you can source the correct paint, and do the prep yourself. You might take it to a detailer to see what they can do. This looks like metallic/clearcoat paint -- so the oxidation may respond to a polish if the clear is still intact.
Consider pulling the light rings, and installing H4s -- light ring problem solved.
I think $5k invested in cosmetics on this car will probably polish in another $10k of value.
With a decent interior, and painted hood, it could bring $25k easy.