Bruce, leakage was a common problem for the Glasgow, the water on the deck from the paddle wheels gets in through the plastic shaft covers (shown in the photograph). I never found it ever put the model in any danger, just annoying having to syringe the water out after each sailing.
There was an item in Radio Control Boat Modeller, November/December 1991 edition which mentions this problem. The builder solved it by using a 'mudguard' fitted inside the paddle box.
If a copy of the magazine item would be of help, please message your email.
I never carried out this modification to mine as it was being sold (this is something I now regret).