That's really helped, thanks(!!), there is still some haziness in the corners, maybe try again while diluting some lens cleaner in the mineral water? Or should i try the black tape/print/marker method from this thread? I do have easy access to 3D printers and black filament should be available.
Quick tip to anyone wanting to do the same, do NOT use PLA filament for this. It has a very low glass transition temp(this temp where, while still under the melting point, the material will start to become soft), so in a warm environment and the bulb at max brightness it would quickly become too soft enough to deform.