V5C and private/cherished-plate broker - process?

[kmpowell]

Short story;

- My other half unexpectedly bought me a private plate for my birthday, it's not from the DVLA, but from a broker
- It's a plate we had previously discussed months ago, so I knew where it was listed. Upon checking, I can see the plate has now disappeared from all websites where it was listed (which I assume is a good thing).
- The broker is on the DVLA page of approved dealers: https://dvlaregistrations.dvla.gov.uk/dealers/

but...

- The broker is asking for a full scanned copy of all pages of my V5C so they can do the plate transfer to my car.
- I asked if they could send me the V750/V778 certificate so I could do the transfer myself, but they are insisting on the scan/copy.

Now, given this is my first ever private plate, I'm unsure of the 'norm'. All I know is handing over a full scan of my V5C goes against my usual safety precautions of not letting anybody near the V5C due to potential fraud on both the car and the plate.

Am I being overcautious, what is the norm/risks here?

[LooneyTunes]

That's normal: the previous owner won't want their details disclosing.

Have bought via several brokers and all have wanted to do it the same way.