Bike Insurance

Ok I've read all of the threads here about insurance and im pretty much still stumped as to which is best. I think i've reached the conclusion that butterworth and M&s are the best but i'm not sure how under their conditions i would claim for certain parts of my bike. i.e parts i have bought off other forum members which obviously i didn't get a receipt for. I've photographed everything on my bike and me with it but is this really sufficient for butterworth?

You don't even have to say that you got stuff second hand. I asked M&S what they would require if I lost my receipts and they said that good photos would be fine for replacement purposes.

What happens if all your receipts get burnt in a house fire or whatever? Or if you kept them in a lock box with your bills and stuff that some burglar stole? They'll still sort you out.