Hey there Ant, don't fret about this, it's just an internet forum and I'm understand the general rule of keeping perhaps dubious sellers out of here.
Good luck with selling stuff, but as always, be wary of folks that you can't meet and sales where you have to ship. I've never sold stuff like this, sight unseen, so would be wary. Have only sold and bought stuff on local used stuff selling lists, talking to and seeing things in person.
Cheers
And on a more cheery note (not) have fun with Brexit! My family in the UK are not thrilled with the whole mess and uncertainty.