
While this was for knives / offensive weapons, the checklist the counter person was working to was the same for firearms.
The main thing I came away with is that for items under £250 there is no requirement to send photos or 'proof' of what an item or its' value is to the Home Office, it is down to the local person being convinced that an items is what you say it is and that the proof of value is accurate.
I couldn't find receipts for any of my items but got screenshots of websites (here and in the US) to 'prove' their value; if I couldn't find the exact model then I found the 'closest' and used that. The counter clerk seemed satisfied and signed the receipt as 'ok' but she did say the final decision would be with the person / unit organising the surender; in Gwent Police (and I would imagine most other forces) this is Firearms Licensing.
I'll update with how it goes, but im my total claim of £447 gets paid, I'll be a few quid up
