1 inch ahead storage compartment

I created this part for a bicycle project, the bicycle has a 1 inch threadless fork.
It was my goal, to store an spareparts and tools inside a standard bicycle frame (mid 90's).
The storage compartment has a diametre of 21 mm and a total heigt of 18.5 mm. The bottom edges are rounded to fit better into the star nut, therefore reducing the heigt needed inside the headset.
The storage compartment can carry a total of two chain connector pin 9-11 speed and a missing link.
I currently plan to d