I wasn't able to replicate the problem but I think this may have been a build up of water over a very long time that's judging from the rust I found. Also as a preventative measure, I drilled into the base of the channel so that any water getting in there will drain into the chassis leg. I'll try to monitor it for a while, though it will be quite a job to do so. Also changed the windscreen cowl but I'm sure that's jus cosmetic