Wanted name of downloadable programme to sharpen faint images please.

[japeflakes]

levels adjust

[japeflakes]

Scanned in greyscale as far as I can tell.   Perhaps a change to RGB mode (as I did) would help:

[Gadget]

If you use Windows 10,  a very quick way would be to open in Photos, which is the usual way of viewing images in Windows10,  and ~

Click on 'Edit and create' on the top bar.
A drop down menu will offer a range of procedures.
Choose 'Edit'
Select 'adjustments; from the top bar.
On the right side you will see various possible adjustments, use the sliders marked  'Light' and 'clarity'until you get a better image.

Then click 'save a copy'.

This won't give you quite as good clarity as the other two examples  but it's easy and quick. I did this with your example.

[Gadget]

PS - make sure you give the copy a different name from the original when you save it.