Old Photo Restoration Stuck On Scan Lines

I’m attempting to restore an old photo with pretty bad speckled silvering as opposed to large areas. I’ve managed to get rid of the spots but in doing so have inadvertently increased the scan lines presence and anything I try to do to get rid of them with Gaussian blur etc. is reducing the image quality significantly.

I’ve tried a couple of methods I’ve found on the internet but the results are not making much difference. (I tried Moire reduction and adding image from two separate layers – one lightened then one darkened to try to get rid of the highlights but again no real success.)

Not getting much success on the patch tools or heal brushes either.

Any suggestions or pointers on a good fix? I think these scan lines are going to play havoc when I try to colour it.

Thanks

*edit – Apologies, i had looked at the ‘removing texture from a photo post’ however the scan lines present would not be considered a repetitive texture and therefore i dont think this would solve the issue.

see below 60% zoom