A Brush Holder for a Metal Pegboard

Please forgive me for my broken English.
I designed a Brush Box or a Box for other use for a Metal Pegboard with T-Nut Holes in 45mm Wide.
Its ~80mm Hight, 50x50mm and the Wide from the Middle of the T is 45mm.
The Walls are just 1,4mm the Bottom too.
The small Part of the T has a Diameter of 4mm and the big one ~7,8mm

Please let me know if you like or dont like it, so i can design it better.