I like the look of this, I’m getting a quote for shipping to the uk.
I don’t like the idea of it being tilted forwards… or is that a bad photo?
I think the slight tilt would be OK but a bigger middle bit to secure the helmet would make me happier, or maybe a raised lip around the outside
I’m sure you could knock something similar up from stuff you’d find in homebase/ikea
OMC have something similar at their place but made of metal and a bit sturdier looking.
MyYour make something called ‘crazy head’ which is similar and available in loads of colours. More for the home than the garage though.
Crazy Head
The tilt is designed to match the shape of your helmet - Most helmets slant down at the front/raise at the back so it would sit straight enough not to worry about it! 
yup. tilt wouldn’t bother me, they look great.
I’ve made my own helmet hangers out of MDF though.