Need advice on post-processing this photo

[Actinia]

As my signature says, I have been taking photographs for fifty years, and am now trying to improve my technique. The photo below of my wife in a patch of Gunnera was taken in 1972 on Tresco in the Isles of Scilly, and was scanned from a slide. During various computer failures and other mishaps, I have lost both the original slide and the original scanned image. What I have now is just this 640x429px image.



The IQ leaves a lot to be desired, but I am keen to retrieve it since I now have photos of her in the same patch of Gunnera taken in 2007 and 2013, and I would like to create a 'time-lapse' set. I have photoshop and various plugins, but so far, have not been able to improve it. For example, I can get some detail out of the shadows at the top right, but this generates strange artefacts in the rest of the image.

Any suggestions (other than going back to 1972)?

 

[The_Traveler]

There's not much to do.
No usable detail in the shadows that doesn't look terrible when boosted.
I think the idea of going back to 1972 is the best one.

 

[bianni]

Yes nothing in the shadows but lines (twigs?), better to make it dark.