I have an A-5 Belgian made "Sweet Sixteen" that was passed down to me. It was made in 1956 and from the looks of it had never been cleaned.
I was a little hesitant to tackle this one myself, but I rolled up the sleeves and went ahead and did it. I got the owners manual from the Browning website and printed out the exploded diagram (that helped a lot). It was a lot easier than I thought it would be. The hardest part was just braking the screws loose. After that it was pretty straight forward.