The main problem with Primoplan lenses with V coating is that the coating deteriorates, meaning, what lookes like haze is in part haze but then the coating underneath it has cracks and it sort of looks like haze.
Cleaning that is only possible if you remove the coating altogether.
Relubing the aperture ring is fairly easy, loosen the tiny grub screw in the front and turn the ring with the name plate to remove it. Underneath is a spring for the aperture preset ring, remove that and you can easily remove the aperture ring. Remove the old grease adn put it back the way it was.
I never relubed a focusing unit but it seemed to be straight forward, the only problem with aluminium bodied lenses can sometimes be that the grease and ring sort of freeze together and it can be very difficult to get them apart.
Also, there do exist some design variations, a prewar version and at least two postwar versions that I know of. One is larger and I find it looks like a star ship from the side or maybe a fountain.
The older one is smaller and thinner.
Good luck on yours!