SGS2 hard case for handlebar mount

[aagaag]

Can anybody point me to a sturdy metal case for the SGS2? It should open with hinges. Something like the picture attached, for example.

What I want to do with the case is to mount it on the handlerbar of my mountain bike with two cable ties. I am looking for a hard case that might be suitable for that job.

I do not like any of the common bike mounts. I have already lost an expensive smartphone that was mounted with a lesser-quality holder, when I rode through a bumpy single-trail and the phone fell into a ravine...

 

[aagaag]

I should explain that I intend to mount the case on the "handlebar stem" rather than on the actual handlebar. Obviouslx the cable ties cannot be passed through the phone case - hence I would be fixing the case in some plastic slider (suggestions?) which would then be attached to the cable ties and consequently to the handle bar stem.

Attached is a picture of how the contraption looked like with my old phone. Suggestions for aesthetical/functional improvements are of course welcome!