I hope you don't mind me saying ... but YIKES!
That electrical system is just plain scary, and the coolant plumbing is worse!
Who plugs off a heater hose with a (gasp) spark plug?!
I realize that you are installing a Ford engine into a Jaguar, and that nothing appears to be mating up.
My thoughts are that if you're going to be using a Ford (Motorcraft) alternator, you should mate that up with a Ford votage regulator, etc ... unless your an electrical wizard that knows exactly how the system works.
I've NEVER seen a 2-wire external voltage regulator.
A cut-out ... yes, but they are designed for generators on farm equipment.
Wilson # 62-02-5608 (Remanufactured ... about $14.00 retail
NAPA Echlin # VR440 (Brand new ... about $65.00 retail)
This is a very typical Ford votage regulator, used on virtually every Ford vehicle from 1965 into the 80's ... anything with an external regulator. The early versions had points, but it was a direct swap to the electronic version.
NAPA Echlin # VRC-428 ($12.50 retail)
Voltage Regulator Connector
Wiring diagram: (also included below as a PDF file attachment that you can open/view/print using Adobe Acrobat Reader)
Curious too ... how did you make out with water-pump pulley, etc?