"My experience is that every car is a bit different."
I am not Mr. Bird, but Dan’s perspective: Between CSX2001 and CSX2200 somebody (AC, Hugus, Shelby, Ford) initiated many requests for some kind of change in designs and parts. AC completed some cars, Hugus completed some cars, and the balance by one of the shops Mr. Shelby was associated with between Dean Moon place and the LAX facility. Different shops, different teams of people, different general hardware supplies, different specification sets, and yes there were many changes in what landed at dealerships. Think of groups of specifications for many subsystems being put into play with many over laps Yes this week’s final product could be very different than last week’s product. It did not help consistency that none of the shops involved used first in first out inventory control. It did not help consistency that Shelby’s works normally ordered 100 each of most parts and often each new lot had some revision of another. Some revisions were driven by changes suppliers made to their products independent of anything the final assembly shops did and that includes small changes even suppliers like Lucas® made. I have worked on a list for years of changes that have been documented. The current list covering the CSX2001 through CSX2100 cars is three plus pages long. In contrast the cars in the last contract CSX2501-CSX2589 I have just four specification changes listed and two of them are what exact engine assemblies Shelby obtained from Ford.
"Parts were sourced from several vendors, especially fasteners."
Dan: See above, multiple shops with their own general hardware preferences and supply chains.
"Buddy Bar Casting was pretty faithful in providing value covers and manifolds, but Shelby bought parts from lots of folks."
Dan: See above, batch to batch specification changes. Buddy Barksdale’s company supplied five different versions of aluminum ‘COBRA POWERED BY FORD’ rocker arm covers in 1963 alone. Designs were changed for some reason often. There were two different versions of ‘COBRA’ safety clutch bell housing during 1963 alone. I could make a very long list. There are patterns though. You might find a part released in March 1963 in any Cobra finished thereafter but not late August 1964 item in a car sold to its original buyer in July 1964.
"The use of Stewart Warner gauges has been told us Cobra guys as an outcome of Shelby’s opinion that Smith gauges were unreliable. Thus, around CSX 2200, they changed to SW, adding the Rack and Pinion steering, changed out the steering column, and used a early Ford Fairland wiring harness to replace the Lucas system. This made the car more serviceable by Ford dealerships in the States, and eliminated many of the demons found in the Lucas system."
Dan: Many changes in chassis and finished cars CSX2201 and later were initated by Ford Motor Company. Ford became Mr. Shelby’s boss at CSX2008. (The original and revised contract in 1962 is very educational.) Ford tested CSX2004 and started using CSX2008 to test things like a Ford electrical charging system before converting it into a concept car. CSX2126 finished before CSX2080 was a test car for most of the changes that got implemented at CSX2201, including the new Ford-McCord cooling system components, Ford American style wire looms (There is nothing Fairlane about Cobra wire looms. Said another way, no amount of modification of a Fairlane's electrical system will come up with a Cobra unique system.), and Stewart-Warner (SW) instruments. The SW tachometer sender, tachometer, tachometer wire loom, and temperature sensors were all unique to CSX2201 and later Cobras under Ford Motor Company drawings and specifications. I will stop there as my electrical system list for CSX2201 and later street cars is 33 pages long. Many of the parts started off as a Ford drawing or specification. Most were made in the USA by Ford top tier suppliers. We have found Ford components made in America dated in the summer of 1962 installed by AC in chassis CSX2201 and later. Ford worked on electrical components for a long time, it just did not happen by accident.
"at this point, but many of us in the US accept the fact that every Cobra is a little different from the others."
Dan: They certainly are but almost entirely due to owners, especially after CSX2201. I very large factor driving changes is buyer morphing the car the bought into the one they wish they had. We interviewed a fellow at one convention that was planning to change his super original unrestored late CSX21xx car into a replica of a CSXsomething car Mr. Shelby had on display at the event. He took his car to the event specifically to see what all he had to change to make his very nice car mimic a replica fitted with many modern updates. He was planning on cutting out the welded in side vents his car came with and installing fastener fixed replicar ones that would make repainting the car easier. Ouch!
One of the things I do is help current owners come up with educated guesses as to how their car might have been day one no matter what it is like currently. I have many subject specific files, windscreen frames is not one of them. Between pictures of mostly unrestored low mile cars and parts plus data files I have collected around 15,000 files. I have data I have collected since circa 1971 as to why is this Cobra different from that one. Yes it was confusing back then as CSX2144 and CSX2465 were parked about a mile apart and they were very different in components. I learned why over time. To have any idea how a new Cobra might have been day one is you have to know when AC Cars finished the rolling chassis, which shop and in some case which employee set finished the chassis into a running car, when by date was the chassis was completed, what type of engine was installed, and the serial number of that engine, and what was ordered for that chassis. In some cases you need information from the AC chassis ledger. Factory pictures help as do some of the new car road test pictures and text.