You can see a nice picture of an Ultra 6627 - 19" Dual Standard with VHF radio (900 chassis) -
HERE
Note the three position system switch - Radio | 405 | 625
The VHF Turret Tuner then has positions for Light, Home and Third
There was definitely a rental version of this set. I had a near identical set as a teenager, but re-branded for "Robinson Rentals". It had the same control panel layout but, if I recall correctly, it was a burgundy colour, with the CRT being protected by flat plate glass. I obtained it from the small TV shop repair I was was working in at the time in lieu of some wages. The boss was shrewd enough to know that he would have difficulty selling such a dated looking set secondhand at that time (1976) as everybody wanted push through and squared off tubes by then, so offered it to me. It served me well as a bedroom set though.
As far as I recall, when the system switch was in the radio position the HT was cut off from the Line and Frame output stages and the heater chain was also altered to place a wire wound resistor in circuit to compensate for the unwanted valve heaters (so not much actual power saving in radio mode!). The LOPT was of the previous 850's pitch overwind type with EY86 rectifier, rather than the later "jellypot" tripler combination - no flywheel sync board, of course.
Unfortunately, I've never managed to find an example to transport me back to my youth. Another case of, "if only I had kept it"!
A bit more info on the Ultra 6627 can be found in this older thread -
HERE