LeapMatic sent me some MaticBox cases for Raspberry PI 1, 2, 3 and 4, they have many mounting options including Top Hat DIN Rail or can be used just on a deck. they also support an internal 2507 5V fan and allow for small heatsink on the PI, here is a link to their site https://leapmatic.com/
to get yours from
Amazon USA
PI 3 https://amzn.to/3bQgqFZ
PI 4 https://amzn.to/2ZZpwe9
Amazon Canada
PI 3 https://amzn.to/2NFew3h