Hi Robert,
I worked hard to find a tank to line up exactly with the carb on my Tiporare and after using a round section Dubro 12 oz that is within a half inch with the pickup tube in the middle height of the cork, and perfect with it rotated to the bottom, Tony told me that it didn't need to be that close. He says his is almost and inch higher and you saw that it ran like a top. I think you're alright with what you have.
Don't be re-inventing the wheel, that's my motto!
Chris...