Also a couple more pointers that may help you..
The extra wiring plug on the New Hollands, back behind the seat area is for a NH rear-facing implement light. I think this light might only be 35W, it may be 55W. But either way, this plug would only be good for 1 light. The reason, is because when dealing with a 12V system, (low voltage), you have to have bigger wire for everything. For example, if you were running 2 55W lamps in your 110V house circuit, the current draw would only be 1 amp. Now run those 55W lamps in a 12V tractor circuit, you are drawing 9 amps! On my tractor, I am running 2 80W Hella lamps facing forward, and 1 55W PIAA facing backwards. That is upwards of 17 amps of current draw, so I had to use some big wire. Make sure you use the proper guage wire for the current draw you are going to have. Current draw is (total wattage divided by circuit voltage). If you use wire that is too small, it will get hot, degrade over time, and could damage other components in your electrical system. If anything, use wire that is too big. If you are real serious about lighting, you could spend about 250.00 and get an HID worklight for your tractor. In this case, you would only be pulling about 3 amps, and would have about 5 times the light output. But it is pricey.

Someday I am going to do it. Good luck with your light project!
-Brad