With modern cameras it's only months

UK estate agents are not allowed to present properties for sale using 'doctored' photos. You might want to check your local laws before using this modified image in any 'for sale' literature.

Great looking house though. I considered living in France many years ago, but ended up in Spain. There's much more bureaucracy to tie you up in knots here.

All modern Pentax DSLR's can be used manually, even with old screw mount, K series, and M series lenses. So the answer to your question is the Pentax K-3 (you didn't stipulate film camera). There's no need to dig up a dinosaur.

Stands back to avoid flying daggers

Glad to hear you've got to the bottom of it, but Windows will not have changed settings within an application, the user can and often does, Windows itself can't.

Unless you have other serious issues with your Windows installation, your imaging problem is not a good reason to do a complete reload.

Are you saying it was not set to zero?

The vignetting on the two samples supplied look identical to me, which leads me to think it's a post-processing issue.

In camera, there is a digital filter setting > Custom filter > Shading Level. If this is set to a negative figure you will get black vignetting. A positive number gives white vignetting.

The digital filter however seems to be applied on a per image basis, so it's probably not that.

As has been suggested, take a couple of JPG images and open them in Windows to see if the vignette appears.

Also, I think the 77mm Ltd lens has the standard smc coating so your HD lens is 2 generations of coating newer than that which is on the 77mm Limited lens.

Wire coat hangers suitably re-shaped.

+1

Purple fringing aside, the 77mm Ltd is a portrait lens, designed to produce soft focus at wide apertures. In this case it's a feature, not a failing.