@Templar is correct. There are a number of factors at play here, and his conclusions reflect his study of these issues.
First of all, Leo Fender was a notoriously thrifty guy. If they were switching to black hardware, Leo would insist they use up the remaining chrome ones rather than dump them. And, to streamline the operation, necks were made in batches. I’ve seen necks with the exact same date on them. They then got mated to bodies, which also were made it batches. Depending on the orders coming in, that might mean a maple neck or two sat on the shelf until it was needed, and that might be a couple of months. A difference of 3-6 months between a neck and body date is not uncommon at all.
BTW, this is true for anything Leo was involved in - pre-CBS Fender, Music Man, or G&L. Leo was a very practical guy by all accounts. If there was a customer who wanted something special and was willing to pay for it, Leo found a way to get it to them.
I’m sure I’ve owned a bass with a smooth black bridge and control plate, but a chrome neck plate. Maybe even more than one. I’m pretty sure I owned one that mixed the smooth and the crinkle black as well. They needed to get product sold, not satisfy historians some 35-40 years later. G&L was not a roaring success out of the gate, they were doing everything they could to stay alive. If you don’t know the story of the Broadcaster/ASAT guitars, it’s worth looking up. It was a stunt designed to provoke a lawsuit - in the hopes that the attention might save the company. And it worked!