The original Marchal mounted to a flat plate that is bonded to the inner body. The 3 holes are necessary to adjust the light both up/down and r/l. How would you adjust the light otherwise with the body on the car? In the picture below, the plastic piece is threaded and rivets to the mounting...
I watched the video. Clearly a "racing" gearbox which drives that price. He says the dimensions are the same as the "other" gearbox on the market and they designed it specifically for the GT40.
You should never lift the tub in the middle using a 2 post lift. The tub jack points are at the front and rear corners on the outer edges. Block with wood and a rag. You can also jack the car using the sub-frames with a lift bar in the quick jacks.
Be very careful of Coker. I bought a set of tires from them (after specifically asking what the date codes were) and got a 4 year old tire (these were not Avons). Are you good on the 225 up front. I am using 215's. Did you check Lucas Tire in Long Beach?
It happens all the time. Mainly from lack of use. That's why I don't waste money on those batteries. Autozone battery is cheap and lasts 3 years. I just get a new one every 3 years. $50 bucks a year.
Dead batteries will show a full charge of 12.X volts but are still dead in terms of having an ability to start your car. Ask me how I know..... I also had my battery on a charger and it showed fine and the charger thought it was fine but it was dead. Again, ask me how I know. Not sure how...