Depends upon your definition of what constitutes working "properly."

The Takumars will mount on other M42 screwmount cameras.  They will focus
correctly.  But the SMC Takumars, with their proprietary full aperture
metering lugs, will not operate in that mode--you will have to stop them
down when metering, just as you would have had to do in any of the Pentax
models that preceded the Spotmatic F.

So, the more correct answer is that, yes, the lenses will work on other
cameras, but you will not be able to exploit the full aperture metering
functions on any but 3 camera models: the Pentax Spotmatic-F, The Pentax ES
and the Pentax ES-II.

I have mixed feelings about full aperture metering.  The meter on the
Spotmatic-F comes on automatically whenever the lens cap is removed.  I
shoot with lens shades a lot, and that necessitates my unscrewing the lens
shade and replacing the lens cap, just to shut off the meter between shots,
in order to conserve the battery.  On my Spotmatic IIa (the previous
Spotmatic model), the meter is activated by a switch, and it automatically
shuts off after the shutter is fired (or it can be manually shut off using
the switch), which allows me to leave my lens uncapped with no risk of
depleting the battery.  I much prefer this to the automatic activation of
the Spotmatic-F.

The price to be paid is that the Spotmatic IIa does not support full
aperture metering.  Frankly I am quite comfortable with stop-down metering
on the Sp IIa.

The ES and ES-II camera support full aperture metering, and their meters
come on when the shutter button is pressed down halfway.  The meter does not
activate automatically whenever the lens cap is removed, like on the
Spotmatic-F.

There is a compromise that exacts a price on these models as well: the ES
cameras were oriented primarily toward aperture priority automatic exposure.
There is no metered manual mode.  If you switch the camera out of aperture
priority mode, the meter shuts off.  Yes, you can operate the camera
manually, but you'll have to use a handheld meter.  Also, the selection of
manual shutter speeds is limited--there are not as many speeds available as
on the Spotmatics.  So, the ES models are a pain for shooters that want to
take the controls manually.

In fairness to Pentax, the ES cameras were produced at a time when exposure
automation was in its infancy, and there were bugs that needed to be worked
out.

My current favorites are the P3n and the P30t, that use the "A" series
(Ka-Mount).  Those cameras have full metered manual mode--just like the
Spotmatics.  They also have aperture-preferred exposure, just like the
ES/ES-II.  They have advanced meter cells that respond faster and do not
have the memory effect of the CdS cells that were used on the M42 bodies.
They have reliable Seiko-Asahi electronic shutters.  They have memory lock,
allowing exposures to be locked in while the photographer re-composes the
shot (you can meter on the subject's face, for example, and then shift the
camera angle without losing the exposure for the subject's face).  They have
dedicated flash units that feature automatic flash exposure (non-TTL).  The
"A" lenses were optically redesigned to be sharper than the previous Pentax
lenses, and they featured multicoating on all lens surfaces (some of the SMC
Takumars had uncoated lens faces, like the front element of the 35mm f/3.5).
They had a program auto exposure option, which was specifically set to
minimize the effect of movement.  Pentax program mode always sought to use
the fastest shutter speed available in a given shot.  Some photographers do
not like that, but I think it is great.  If one wants to use slower shutter
speeds, or control depth-of-field, just switch to aperture priority mode.

So, for me, the P3n/P30t models offer all the features that I liked in the
Spotmatics and the ES models, with none of the compromises.  No MLU, but I
haven't found that to be problematic.  And the camera dies if the batteries
go dead, but it is hardly a burden to carry a backup set of batteries.
They're good for 10,000 exposures, and I'm not planning to spend an extended
time on some desert island.

The best thing about those models is that they afford full control to the
photographer.  You want manual--you've got manual.  You want auto
exposure--you've got 2 different auto-exposure modes.  You want dedicated
flash--you've got it, and you can also operate the flash manually, but I
can't imagine why anyone would want to.

Oh, and you have full aperture metering, along with depth-of-field preview!
For me, that's everything I require.