Quick-release Mod for CREE T6 Bicycle Light + Waterproof Battery Bottle (cheap/free)

Picture of Quick-release Mod for CREE T6 Bicycle Light + Waterproof Battery Bottle (cheap/free)
I bought this kind of "upper beam headlights" for my bike:


Maybe not the safest electronics* but dirt-cheap and bright as @$%&.

Disregarding some safety issues* I was annoyed by the cumbersome way of attaching and detaching it to my bike.
Well, ok, the included mounting material some kind of works, but... Meh.

So I was thinking about some quick-release solution for days and days until I had some bright moment when I saw my mini spring clamps, pretty much identically constructed to these:

or maybe more like these:

Against all my expectations this worked so fine as it had been made for that purpose...
So see the next steps.

*Not waterproof as described and the low battery warning does not work, instead it suddenly switches off, leaving you in the dark. The included charger / power supply gets pretty hot if the battery is fully drained. You´ve been warned!
But disregarding those 'minor' safety issues, it works fine ;)

Step 1: Materials

Picture of Materials
Headlight mount:
CREE T6 Bicycle light kit or sth. equivalent
M4 screw
Mini spring clamp
Optional: piece of road bike inner tube
Optional: butyl sealant

Battery bottle:
PET soda bottle and twist-off cap
Insulating tape
Optional: piece of foamed plastic
Optional: butyl sealant

(No extra pictures of the materials needed for the battery bottle, I forgot in fever... See annotations in the pics and have mercy.)
making one thanks