I have the same style trailer (with the murphy bed). You did not say of the item was any type metal or size. If it metal a magnet would draw the lost item out.
Now, If you reach into the storage area to the front of the trailer you can determine how deep the floor over hang is (its not but 5")
You can remove the bed frame from the hing, lift it out and have complete access to that over hanging floor - lip area. You, of course, now have complete access to that front arera. While you are there suggestion, I placed a piece of 1/4" plywood completely across that lip area securing it to the floor. I had dropped a screwdriver back there and KNEW losing stuff in that area would be very hard to retrieve in the future, so I covered it.
hope that helps.
2018 Wildwood X-lite 230BHXL
2008 Ford F-150 5,4L