Well done on finding British Museum reference.

I was hoping that the raw data would allow you to plug in the figures to latest calibration curve with the current estimate of half life.

A very monor point:
Isn't the reference date before present 'BP' taken as 1950, so minus 3990 years would be 2041 BC as there is no year 0 with one year from AD 1 to 1 BC?

Isn't the date 2670 BC plus or minus 108 years from your calculation.

If so then well done.

This is a big difference from Spence theory and half way between the historical date of 2570 BC and potentially 2770 BC as your theory.

It is known that New Year's Day in Egypt in AD 139 coincided with the rising of Sirius at dawn, so 2 x 1460 years earlier is 2782 BC by calculating AD1 to 1 BC as one year. Edwards also noted a date of 2770 BC from more precise astronomical calculations, assuming the integrity of the Egyptian calendar.

In the 2013 Oxford paper I think I recall reading that an individual sample could only be expected to give a date of plus or minus 100 years, but that a large number of samples would give a much more precise date from statistics.

The re-evaluation of this sample would be a useful academic exercise to assess the quality of radiocarbon analysis in 1970 by comparing the old raw data to new raw data taking into account the sample is now 50 years old if it was actually done in 1970. The paper by Edwards did not actually state when it was done.

It seems the Oxford study would be improved by looking at samples from the Fourth Dynasty, so I think there are two reasons to re-evaluate this sample.

Engaging with the Oxford academics seems a good idea.

Mark