I don't know of kits , per se, but Vaillancourt's L-19 has Fowler flaps, and I 've seen an L-5 Stinson, either a Vaillancourt or Ziroli, that has Fowler flaps. Both have the offset hinges and can be built with concealed linkages; the BirdDog's flaps will go to 45 degrees, not sure about the Stinson. On both planes the hinges are built up, and not available as separate hardware.