I've just purchased a 79 H30 in need of some cleaning and fixing,so I'll be here often. Thanks for the help all. The bladder tank has been removed a long time ago and I ordered the retro kit and other recommended parts from raritan to make the head function. I need to install a holding tank and vent system. Is the port vberth storage compartment the best place and has anyone installed one there before ? If so do you have a tank make and model that fits in that area ? As you can see in the attached photo the previos owners solution worked but may not have been the best answer. Thanks