Water Softeners and Air Filtration Systems - Kinetico 60 Head Leak

Hey Guys...
I bought this home about 5 years ago.... the kinetico has worked fine for 2-years and 3 years ago it started leaking.
3-years ago I did not know where from?? I finally located the leak at between the metering head and the manifold it connects to. Over the last 3 years, I've slowed or stopped the leak by tightening the (7) bolts on this head.... But I'm afraid
on this last tightening episode... I might have gone to far!!
My question is if it is possible to dismantle this head and insert a new gasket? My local dealer will cost me way to much to do this. I know my way around pressure & hydraulic systems.. and I can even die cut a new gasket. I would prefer to buy one, if it's reasonable....
I have no documentation on this unit and I'm not even sure there's a gasket... but surely there has to be... Are diagrams of the parts and assembly of this system available ?
Any help or suggestions would be appreciated.
frank

I've always know that if the head leaks between the diferent levels, replace the main base not the seals. The main base is what the screws go into. It also connects the 2 tanks together.