I would be quite willing to wager that many of the subassembly parts like pins and steel stock were simply purchased from a chosen supply house based on dimensions with nominal understanding or concern as to proper hardening or application Simply a matter of "I need a pin this big or bearing with that diameter... part 123xx looks good" Couple that with the apparent inability to hold a dimensional tolerance on locally machined parts, and outsouced & unchecked/uncheckable heat treating and you have the recipe for disaster.
In comparison, the Ford parts were very high profile and low volume. Somebody would be watching closely, and way too few for any real production run. Probably made in the prototype shop areas of Ford or their suppliers. Given those resources and skill sets, they are likely far better than normal production parts in terms of dimensions and treatments.
