Panel revision

I've tweaked the design yet again; if I use 4-way connectors, I can get rid of half the 3-ways, plus the connections between the.  Of course, the 4-ways need to be less than twice the price of 3s.  Not always the case.

The big question is to use tubing for the 'manifold' or to use NPT.  If I use nipples to connect the manifold pieces, they'll be quite tight.