Super Sneaky Steve,
Man, I literally cut my teeth on top-breaks. Bought many when I was a kid and they could be bought from second hand shops or junk shops for $1.50~$2.00. Most wouldn't fire but I could get them into shooting shape for little or nothing.
My favorite was a pristine Marlin .38 S&W with nickel plating. I had the service station build up the frame lugs with brazing rod and filed them down to correct size, and made a pair of target stocks from walnut. Gave it to a friend of mine, who gave it to a girl friend whose husband took issue with that.