update. after a good deal of thought i have decided that my plenum lower drain fitting yesterday was indeed a success. having trawled a number of posts regarding original fitting of these rubber plenum tubes, in the manner deployed upon manufacture, it was not a good one. all around the mounting holes both ends of the grommet seal were covered in rust. not good. this would also indicate rust is attacking the lower chamber mounting holes. indeed it does,probably they would or should have been sealed with a type of mastic . so tomorrow i will pop all of my unsealed ones out and mastic them. this should stop the leaking of rubber seals around the holes and letting water into the chamber undercavity itself. i will leave the exit tubes free standing after cleaning up the areas first and treating with a rust treatment and either paint spraying or mastic covering. this will also let warm air circulate inside the under chamber. so all in all a good outcome . ...
i only use an old rover 75 sump dipstick to rod my plenums,which i check regularly through my spyhole mod. i also have the jules mods and never need to rod them heavily. if others are worried about dislodging the tubes again, just masic them back in after a good cleanup.