Gear/wing brackes

[grdev]

I wonder if a few 1/2" holes would be OK to remove some excess material?

[Sam Buchanan]

Looks good, Jim.

Another option would be to go ahead and weld in the standard brackets, then weld extensions to them for the pulley when you rig the plane. That would still have the advantage of fewer parts count and hardware, but still easy to custom fit as necessary without needing to know dimensions in advance.

[Jlwright]

It looks like I will have to butcher nearly all the brackets to fit around the tubes. There is only one corner that they will remotely fit. Am I thinking right?
Here is a cardboard template that roughly shows what has to be cut away.