Here are a few photos of the brass and steel fittings in place and the steel pipes etc.
Layout.jpg
Brass 90 degree fitting connecting the passenger side heater matrix to the suction side of the water pump;
Passenger.jpg
The steel pipe running from the outlet of the passenger side heater matrix to the suction side of the water pump;
Passenger 3.jpg
The steel fitting (unobtainable) connecting the short steel pipe from vacuum valve to the passenger side cylinder head, this is where the passenger side heater matrix is fed from;
Passenger (2).jpg
The other end of the short steel pipe on the passenger side has the vacuum operated water valve to feed the heater matrix on that side (note the brass hex union half fixed (silver soldered?) to the end of the steel pipe ..they come as one item);
valve.jpg
The drivers side is a lot more difficult to photograph because the air box ducting gets in the way. There is a 90 degree brass fitting below the steering pump screwed into the back of the water pump (suction side) and this connects the long complex shaped steel tube in Barry's photo in the previous post to the pump. At the other end of this pipe there is a heater hose that connects it to the outlet of the driver's side heater matrix.
The inlet to this heater matrix is fed from another 90 degree brass fitting on the driver's side cylinder head connected to a medium length steel pipe then onto the driver's side vacuum valve (you can just see it on the left of the photo), then by rubber hose to the inlet of the heater matrix. You can see this steel pipe running alongside the exhaust header in the following photo;
driver 1.jpg
If you go down the route of making your own steel pipes then you'll need the union nuts, available from several suppliers like this one (be careful on alignment when screwing them in because they cross thread pretty easily);
pipe flare nut.jpg
The steel fitting on the passenger side is unobtainable (please someone prove me wrong) but to can get a brass version but it would need re-machining to change the 1/2" NPT to 3/8" NPT assuming the ID was small enough to do that (otherwise you'll need to add a 1/2" NPT female to 3/8" NPT male (not pretty since the overall fitting will be quite long));
Brass fitting instead of steel.jpg
...you'll save yourself a lot of hassle if you simply find you can buy a set of second hand steel pipes from Jack R. at MarkII Enterprises or Old Lincoln etc.