I've gone down this trail of breadcrumbs and would like to see it through, in the end, I'll let it go, but it'd be extremely satisfying at this point to get the answers. Also, what do you mean by "serious"? Like I'm too serious, or just am willing to give too much for something that's not worth it? Or neither? Feel free not to hold back.
You are giving off a vibe that suggests this is so important to you that you are not willing to let it go even when someone else might. That is not negative but it is noticeable and unusual.
But let's back off and try and distinguish facts from speculation.
I have personally seen a production log book from New Hartford. Hans has reported various production records recovered from dumpsters at Westerly.
But we don't actually know what production logs were kept at Corona. We don't know what information they contain. We have speculated that there was some kind of paper record. If such a record existed we don't know whether it exists today or where to look for it. FMIC may have it or CMG may have it. It is quite possible that the holder does not realize that they have it
Even if the information exists it might not be shared. Unpublished information is valuable to Hans and he may choose not to share in order to protect future revenues from when it is published. (This is not to suggest that Hans has, or has seen the records). Guild at New Hartford considered production quantities proprietary. Perhaps the holder remains under an obligation not to share or disclose.
So the very first thing you should do is ask Hans what he knows and will share. You might be surprised and the answer might shape your next steps.
I would find out what information is embedded in a serial number and how they were assigned. That will help figure out whether production estimates for a model can be derived from serial numbers, or not.
I would try and find someone at FMIC and at Guild who understood about archives and ask questions about what records might exist in storage. The right person would understand that your interest is in availability and not contents, at least at this time.
Finally I would try and locate someone who worked at Corona while Guild was there. What they can tell you about operations may lead you to other questions or sources.