I had a Merkel O/U shotgun stolen in 2004. I went to the dealer I purchased the shotgun from and they would not look it up for me. They said they didn't have the time to mess with it. I haven't darkened their door since. It was a $6K gun and I had bought several rifles from them also including a Dakota Safari. I wasn't the type of customer that comes in before hunting season and buys a box of shells.
My current dealer says that they will be glad to provide any purchase information on any firearm I have purchased from their shop
I've never tried getting any numbers from the BATFE.
I'd try retailer first....
Did you offer them $$$s for their time to look??
They weren't interested in helping in any way, no matter what. I told them I could narrow it down to a weeks time and they just said no and walked off.
I had my receipt, it was just that most of it had faded away and It wasn't possible to read the serial number. I found out later that Merkel puts the serial number in the booklet they send with each firearm and I still had the booklet in the case for the shotgun. So I got the serial number reported to the LEO.
I take a picture of those printed receipts now.