How to resurrect invisible LVM volumes

I had some LVM volumes configured in PCLinuxOS. Never utilised the features, only suffered from the occasional problem or incompatibility. I find the whole thing immensely complex and obscure, so I probably won’t use this again any time soon.

But at least I would like to have access to my old LVM volumes from Ubuntu Gutsy now, and I had a hard time figuring out the correct command sequence to make them visible again (given you know the name of the volume group you want to resurrect):
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