Hi,
yes it's just the punch and reader. It looks like that TX-400/LS.
I found it in Austria.
Overview of the inside of the main half of the device, with the reader top right:
This view is from the left side of the device after I removed the cover for that part, so the front is on the right and the back is on the left.
At the top it's connected to the puncher (rainbow cable), which is in a separate enclosure (they are bolted together) to the back of this view. You can barely make out the roll of black (!) paper tape of the puncher at the left edge of the image.
The black cable in the middle goes to the reader, and the white cable connected to an IC socket (just to the right of the black cable) goes to the back panel. It is also visible at the bottom. Those two cables cross in the middle so it is a bit confusing in the image.
The reader is, as far as I can tell, identical to that of a Siemens T1000. The "padding" at the bottom has deteriorated so it's a bit nasty to handle, but you can see there is a red button and also the blue and red wires to the little LED on the far right.
The puncher is difficult to open so I didn't, but I'm assuming it's identical to the T1000 one, except maybe the interface cable might be different? I don't know how it would usually be hooked up to a telex.
This is what the back looks like, with the two serial ports (male at top and female at bottom) and the DIP switches etc.:
Ignore the DIP setting it's me fiddling around, they were all set to the left when I got it. The bottom one is somehow involved in tape speed, maybe 300 Bd to left and 110 Bd to right? The other three do something but I don't know what.
This is the PCB for the back, the two serial ports clearly visible on the PCB:
It says "COSCOM" and "TX 400LS V0" at the top.
Here is a closeup of the "main" board:
And finally this is what is in the top left corner, but turned right side up for your convenience
edit: I forgot to mention that there is a handwritten label inside at the far right of the "main" PCB marked "OIL 22.2.1985", whatever that means.
= hole, 
= no hole), and finally the same in binary (1 = hole, 0 = no hole):