first carbine unboxing

[Matt_X]

serial number 1959xxx. USCARBINECAL30M1.com
shows sometime between January and October 1943, likely closer to the end? Does anyone know of any other production records?

Interesting website. I'm not familiar with who put it together. Looks like it hasn't been updated sicne 2012.

The book by Ruth & Duff have a table estimating serial numbers with production dates for most of the manufacturers.
Ruth & Duff put your number as July to Sept 1943.

The Carbine Club has spreadsheets which include serials numbers that have been associated with specific dates.
I haven't looked at NPM, but from what I've seen on others - particularly Saginaw - I suggest you use your own judgement in deciding whether the evidence aligns with the proposed date of manufacture. Saginaw has been difficult for a number of reasons and so there can be different interpretations. Each company presents its own quirks for researching and estimating production dates.
M1 Carbine Serial Number Spread Sheets - The Carbine Collector's Club - Page 1