Almost sounds like you are describing Palladiums. A lot of their current styles are pretty ugly but a plain pair might be a cheap option to use as a DIY prototype? Would be suitably unstructured. I'm sure there are fashion brands (Visvim?) that have done Palladium style sneaker boots in the past too. I can't imagine a traditional leather shoemaker being interested in the project. I wanna find that photograph now, sounds awesome.