Exporting/importing knives between UK and France?

[SLT.AMBEMC]

Hello,
I have been trying to sort out the various custom official paperwork to fill when exporting/importing knives between the UK and France as an individual (i.e. my personal collection). Before anybody asks, I am considering the case of legal knives on either side (in practice, this means legal in the UK as almost anything is legal in my home country).
There are 4 things to consider:
1) trip France to UK:
a) exporting from France; I have the answer for that, it is free, nothing to declare to the Franch custom when leaving
b) importing to the UK; can anyone confirm if there is any declaration to do?

2) trip UK to France:
a) exporting from the UK; is there anything to declare?
b) importing to France; well, that is a bit odd, but it seems that you need to fill a demand for importing military weapon and ammunition (which covers fixd and locking knives as they are classified as Cat 6 weapons)

Any additional information is welcome.
Regards