A tonemapped version:

When you are focusing at long distances, the immense depth of field should render everything in focus.

If we are talking about telephoto shots here then it may be that the problem is aerial haze, or camera shake.

Try it again on a firm tripod using the 2 second delayed action to remove any chance of moving the camera. Try say f/8 at a low ISO value and see what you get. The only other thing to remember is that trees and other foliage move in the breeze, so subject movement can affect sharpness too. Therefore, perhaps a building would be a good test subject.

It's not really snobbery. When Chinon lenses were marketed in the UK they were an "own brand" of Dixons and sold at very low prices. Their quality is variable and although I'm sure some can be very good, as a general prospect they are low to middle grade.

I had a 135mm f/2.8 once and it was quite bluish in colour balance, large, heavy, quite stiff to focus compared to a Pentax. Optically it wasn't a patch on the Pentax lenses of the day.

Many shop chains had their own brands, often from various sources. Anyone remember Greens lenses?

The OP can send a PM to a new member, to which they can reply.

The full story will be found on the National Trust website, or Google, under "Dunham Massey".

This where Sue, myself and Ken were today, and a very pleasant day it was too. Dunham Massey is not too far from where Sue and I live, although rather further for Ken.

Pressing the shutter release half way will set off the AF system, so manually focusing first will only be any good if you switch the camera body to MF.

The thread is now in its new home.

Before you do anything, I would research the names and find out exactly what you have. Then you could put them on a library site such as fotoLibra and sell them.

There is an adapter to fit Pentax 67 lenses.

SRB Griturn would be able to advise on anything else that's available, although I suspect we are in expensive territory here, not casual dabbling.