I still have my Tektronix 465 and 475. The 475 is connected to my HF station so that I can monitor my transmit signal. No analog meter is anywhere near as truthful as an analog oscilloscope when it comes to measuring moving power.
I'm not sure what you mean by "moving power", but a scope's vertical spec is 2%. That will also be frequency dependent because of the scope's frequency response and its VSWR of 1.3 (IIRC) i.e. >2dB.
OTOH an HP432 + 8474 thermistor mount is (nominally!) metrology grade: the calibration tewaks for different frequencies run from 100% to 88%, i.e. 0.5dB max. And it works to many many GHz CW only, of course, and it will also be measuring the harmonics that are probably invisible on a scope.
Can I interest you in mine; it is on fleabay
HF comms radio is normally quite narrowband, so 'scope bandwidth of a 475 may be neglected.
An oscilloscope is not normally used standalone as a power meter but would be normally set up to a convenient scale so that changes in the output power would be visible.
An analog 'scope effectively has no inertia, compared with an old-style meter movement, which has inherent errors related to the ballistics of the movement.
Many years back, at my old job, we received a Modulation monitor from a remote AM station, which allegedly was reading high, with the mod scale "twanging".
We sent another off, & proceeded to test the "faulty" one, which was found to be normal, just in time for a report from the "first in" maintenance people that the replacement was also faulty.
The Boss sent two of us off in a van to check.
Arriving at the site, the Mod Mon was happily twanging away.
Grabbing an analog 'scope, the problem was immediately obvious, with the RF signal being driven to cutoff due to excessive modulation.
The MM showed little sign of distress other than the meter "twanging", nor was the audio audibly distorted.
It turned out that the "first in" guys had "lined" the TX mod up using an 8dB lower audio level than the correct one.