Congrats to the Meinbergs the won the 2017 Gnome Hunt! They found the gnome bucket in a flower pot at the caboose.
Here are the solutions to the riddle in the barcodes:
Clue 1: Seek ye the rainbow wizard of Zelda's Zone
Solution: Rainbow gumball machine called Wizard at Zone One Video game store
Clue 2: Best place to find Romance if you are French 440
Solution: Dewey Decimal system of 440 is French Romance. Next clue hidden at library at that number
Clue 3: Park and “Do Your Best”
Solution: Cahaba Lily Park Sign has the words "Do you Best"
Clue 4: Not Old Discord but ...
Solution: Harmony Graveyard historical marker sign
Clue 5: Put your nose to the grind stone
Solution: Sign by the Grind stone in front of Helena Museum
Clue 6: Four Courts but no King
Solution: Hidden at the four tennis courts in Joe Tucker Park
Last Clue: You are at the end of theses train of clues
Solution: End of Train is Caboose. Gnome hidden inside flower pot by caboose entrance