Holley Street Avenger Corrosion!!

[protour73]

I read a while back about Holley Street Avenger carbs that had a corrosion problem, so with the thought in mind of doing some carb cleaning, I got a rebuild kit and tore the carb apart and found this. Has anyone seen this before? Is this the problem that Holley advised about? Or is this something else like the type of gas (with ethanol??) put into the car?

Also noted two different floats, brass in primary bowl and the modern material in the secondary bowl.