There's one sitting here on my desk with a Hoya 35-70 'Profile' lens on the front of it. It was working last time I used it and still has a film in it. If someone will give me £30 for it +postage ............. I can take some pics of it if wanted.

I can thoroughly recommend that bellows (it's the same as the one I use).
Put a 100mm enlarger lens on the front. Final focussing tweaks with live view. It is good for focus stacking too.

Great that someone thought to preserve the log. These are really super.

Thankyou but I have both plastic and metal versions of Pentax and Soligor ones which are a bit loose. The real Meyer jobs have tiny ribs on the inside rim that grip really well.

The front one for either an f4 200mm or f2.8 135mm. Same cap fits both at 60mm. It's a plain, push-on plastic affair.

1st attempt failed - any takers?

Funny you should say that .... ! I was certain that I had done so but clearly had not done it properly -- Yes, it works -- Duh !

I get it to work on the K5 but try as I might, it doesn't seem even to engage on the K3ii. Press the shutter release and it fires, no matter how you have set it.

I have noticed when using Live View on both K5 and K3ii that there is a constant whirring noise, as if something is working quite hard.
I know the mirror is hoisted out of the way and the rear screen is showing just what the sensor is seeing and the software is compensating for varying light levels and all sorts. What I don't know is how the mechanics actually work.
Is there some sort of motor working against a clutch? Is there an electromagnet holding something up? is there a fan going to keep it cool? Will I wear it out by regularly using it? Strange noises that I don't understand tend to worry me.

DTSE ones on Ebay are less than that for a new one (incl battery)