This is actually related to the definition of due definition 6:
[only before noun] (formal) that is suitable or right in the circumstances
After due consideration, we have decided to appoint Mr Davis to the job.
to make due allowance for something (British English)
He was charged with driving without due care and attention.
So the conclusion in the quote is made on the condition that the wear of existing specimens would be considired as appropriate in that kind of situation.
due consideration could also be used in your quote without changing the meaning.