Firstly: https://proofofexistence.com/detail/59842392aaeb2503acc35951cbb1f6cf7629bcc62ba0a0bed02928fc99e85d7a
(to note when I created the document)
and then this: https://ciyam.org/qc_proofing.txt

It could probably be improved but is just a starting point to make sure that we will be able to make Bitcoin QC proof well ahead of any real threat of people losing funds (which I have no idea how far away is).