"Do you have a record of how many letters have been ordered on this particular gun?" No, although Jim would have a record on the work he's done; but we still wouldn't have any idea as to any inquiries that may have been made directly to Cody.
"This is certainly up for debate and an interesting topic, but I disagree that factory record alone determines the grade of the gun."
I don't disagree with your assertion as I've seen several examples where the grade stamp on the gun itself was consistent to that grade, but the shipping record for that serial number recorded the gun as a different grade altogether (some examples: two guns marked A-2 and recorded in the ledgers as PE grades, an A-3 gun recorded as an A-2 in the ledgers, etc.). BUT, whenever Jim is researching a serial number for a research letter, he is obligated to report EXACTLY what is contained within those records whether the information in the original ledgers matches the grade indicator on the actual gun or not. If he did otherwise he'd be altering the originality of the records themselves[ and in effect, re-writing history. Jim's primary responsibility for the records is to make sure they are never, or become corrupted. Think about this scenario, there are serial numbers in the original ledgers that apparently were never used as the gun specification columns are blank. Do you realize how much an unscrupulous individual might pay for one of those serial numbers in order to build a high-grade fake for resale? We simply can't allow such crap to occur.
"We have no reason to believe that every employee in that era was inherently better than what we are experiencing in today’s work force."
Hunter had a finite number of very skilled inspectors, and these guys knew exactly how to distinguish or ID gun grades; so I don't believe for a second that the ledger entries we see were unintentional mistakes. Based on what I've seen to date, those entries (all of which were hand written) recording a gun as a lower grade were deliberate; and most likely done to reduce the sales price as a favor for friend, relative, employee, a celebrity, etc.; or to curry favor from a vendor, a politician, or some other important and/or well connected individual.
"how many guns were recorded in a higher grade than actual?" In all my years of LC research I've yet to see an entry for any gun recorded as a higher grade than was marked on the gun itself; in every case these odd ledger entries were recording a gun as a lower grades than the grade designation on the gun.
"Just a few thoughts. Value? As always...What the buyer will pay. Or is it what the seller can fetch?" The value of a vintage gun has always been, and remains to this day the price a willing and able buyer will pay. In my opinion, when a knowledgeable collector (one who's done his homework) finds a gun such as some I've depicted and discussed in this and the other thread, he'll always be open to paying a premium for ownership. After all, he'd be purchasing a rare and unique one-off; and how often can one make that claim?