Combination of rotary switch and potentiometer

I need a combined rotary switch/potentiometer.
As fas as I know, Elma has a solution for this, but this is a pretty expensive solution...
Is there a more affordable solution for a rotary switch/potentiometer combination?
I saw a picture of a TK Audio product, but I have no idea what the brand of the switch and/or the special potentiometer shaft could be.
Any ideas?

There are grayhill rotary switches with hollow shafts to use pots. User PotatoCakes was selling some here

https://groupdiy.com/index.php?topic=66292.20

The switches in the TK Audio equipment look a bit like the TT Electronics ones.

I took apart an old oscilloscope a long time ago, and it had a sort of modular rotary switches system where the individual decks are PC mount, with either a very long shaft through them, or a sort of hollow coupler which allowed a potmeter shaft to sit in the middle (IIRC some had the dinky thin shafts, 4mm?). I threw them out during spring cleaning earlier this week, but they are still in the bin, so I can see if they have any branding or type on them. It was a really old scope (early 60's, I think), so I am not sure if this is still something which is current.

Something like these: http://www.nsfcontrols.co.uk/home.aspx
Probably heinously expensive though.

Not inexpensive, but Blore Edwards makes them.  https://www.blore-ed.com/