Export BCI from Romania to UK

[HelixSpri]

Hi! I really need some help bringing my female Boa Imperator from Romania to the UK after Bexit. I know I need a CITES export permit from the national authorities of Romania and an import permit from the UK authorities, however in order to get the export permit it looks like I will need a receipt from when I bought her or some other proof showing the seller.
The problem is that I got this snake some 10 years ago when I was a child and my parents threw the receipt away. My snake currently has a health certificate and an European animal passport (and is microciped), is there any way I can get a CITES export permit using these documents? Has anyone else exported reptiles from Romania or knows how to get a permit without the receipt?
Note: The reason why they need the receipt is to check if the petshop caught the snake form the wild or if she was captive bred (or where they got her from overall), taking into account how common the species is and that my snake is very soft tempered, I think her and her ancestors were captive bred for multiple generations. Also she was some 5-6 months old when I got her so I don't think she was imported from outside the country either.