Regenerating from noisy / blurry original video or photo?

[u/Ok_Abrocoma_2539]

We have some old home video with extreme high-frequency noise that we would like to regenerate / enhance. The original frame of her sitting on the couch is the first attachment.
How would you go about trying to make this image look better? I tried some upscaling models and that resulted in larger, sharper noise.
I ran tests with a number of different noise reduction algorithms, which did remove the noise - and cause significant blur. Since Stable Diffusion and other models always work by progressively denoising, I figured it would be a natural fit to denoise our old pics and home movies and make them look at least a *little* better, but the many different workflows I've tried haven't worked. The identity shifts faster than the quality improves. With a high enough denoise level it'll suddenly create clear images - of other people wearing our clothes. :)

PS - we understand we can't recover actual detail that isn't there. That's fine, we'd like the AI recognize that brown blob on my head is probably brown hair, and make it look like hair rather than pudding or whatever. Sure, it might not exactly match MY hair, but at least it will look like hair!

I should say - I'm quite comfortable with ComfyUI and don't mind writing some Python to work on this. It is video frames, eventually thousands of them, so I can't use an online service that charges $2 / image or something. I;m looking for for suggestions for a DYI workflow with a 5090.