Thanks for all the opinions, guys.
The bottom line looks as follows to me:
a. If the buyer is genuine I’m OK to refund now – either way this needs to be done and the buyer will probably send the money again if the shock shows up.
b. If the buyer is a scammer then I’d better wait for Royal Mail claim – this is the only way to make sure I receive the default £46 cover on 1st Class postage or can prove the shock’s been delivered.
I really don’t have any grounds to believe the buyer is a scammer, TBH. But the idea of just sending away money after honestly posting the item is hard to get used to 🙂
And – yes, I’m agree that not paying insurance is not the best idea. For future cases, in order to make sure I get the insurance do I need to go with the claim first and really verify that it’s missing or do I just tell Royal Mail “It’s been lost” and they pay the money no questions asked?