Thanks for the heads up.
Unfortunately, Mr. Butler has long ago fallen off the radar and is no longer active in modeling circles. I know who has his 1/35 AH-1Z masters, but there is no plan to make sets since they are very crude and not really suited for casting.
There is word that Kitty Hawk is working on 1/35 versions of their excellent 1/48 AH-1Z and UH-1Y kits though. So keep your eyes peeled for them.