How very odd. I have a K10D and the Super-Takumar 135mm f/3.5 screwmount lens and genuine Pentax m42 K-mount adapter and I can confirm that the aperture does not close down when I press the green button in manual mode and lens set to "A"uto.
I repeat No K-mount body has the mechanism to auto stop-down screwmount lenses.
Here is a Spotmatic II. The Auto Stop-Down mechanism can be seen at the bottom of the lens mount opening.
Here is a K10D. Other than the power zoom contacts there is no other mechanism at the bottom. Certainly nothing that would operate the pin on a screwmount lens. The K-mount auto stop-down actuator tab can be seen on the left (9 o'clock) in the mirror box. Remove the lens and adapter. When you press the green button you will see and hear this tab move. Does anything by the power zoom contacts move?
If you have a mechanism at the bottom of the mirror box hold on to that body as you have something totally unique. Post some pictures. Better yet take a video with your K-1 looking through the front with or without Takumar mounted on the K10D showing the stop-down in operation with the green button.
Note: The actuator will always operate on the K10D regardless if or what type of lens is mounted. The K-5 and later models including the K-1 series the actuator will only operate with lenses that short out the "data" pin. That's why you don't hear the actuator on the K-1 with screw-mount lenses unless you use an externally flanged bare metal adapter.
Last edited by Not a Number; 07-01-2018 at 05:28 AM.