I’d assume just reversing the outer lug connections on the volume pots. As original, volume knobs fully ‘up’ would be no volume and pickup output signal would be grounded, giving the 0 ohms reading at the output jack. But maybe also checking the connections to the output socket as well. There could have been two issues giving the same result.

But it would be nice to know exactly what the issue(s) were.

Very glad to know it’s all up and running. Nice when it works first time, but you do tend to learn more when it doesn’t.