I've had both LPs out today to compare them and here's the findings:
Pearl - 10mm thinner body than the GIbson, neck angle is shallower, neck volute, wider late 60s style headstock, weight is 4.6kg (10.1lbs), it has a light and airy biting sound. There is quite a bit of shrinkage around the neck joint which has cracked the finish, and possibly the wood(!). The joint seems stable though so I'm not concerned. I'll keep an eye on it. I'll get some chrome covers to add to the witch hats (which look great!) to finish it off.
Gibson - weight is 4.7kg (10.4lbs), heavy and dark sound. I've got some unpotted Zebra Mules on order which will finish it off nicely :)
Here are the two LPs side by side:
