I have documented a lot more since the prior threads. Some "260" engine and Cobra questions get messy answer wise because there were parts and practices by Ford's engineering and production departments, parts and practices by Shelby's works, parts and practices by Hugus' works, parts and practices by A.C. Cars' shop, and no telling what Holman-Moody did with CSX2009. The "260" engine section of my Cobra Engines commentary is around 16 pages and that does not include much about the racing 4-2V prototype and production Weber carburetor based racing details.
A simple question like cylinder head casting engineering number (all verified have been XE-10021 plus a log book serial number) is easy. What Ford carburetor spacer was used (a remachined to modify an existing production part to suit a Ford 4100-A 1.12 size carburetor) is easy. Many others need qualifiers to go them beyond early or late (like two cars are known to have had such and such throttle linkage, one or two this kind, and all the rest this kind) depending on which shop finishing cars in which country did the work and when they did it. The main folder with the information collected when Bob Mannel did a reverse engineering study on unrestored mostly intact ex-Cobra engine XHP-260-4 for us takes up 3.6+GB of digital space with 1,863 files in 12 subfolders by major subjects and gets down to comparing actual measured cam shaft lobe profiles in charts. My slide show on mechanical fuel pumps used in Cobras has 30 pages covering the mechanical fuel pumps, fuel filters, and lines Cobras of the time 260 c.i.d. engines were used.