I needed an RPI4 mount for my MK4 and couldn't find anything so I grabbed Hazi's case as a start because it was a snap case and had a 40mm fan. I added a mounting hex for the MK4 frame. I added a M3Ns to secure it to the frame. I also added a spot for a reset button and power led.
Push button switch: https://www.amazon.com/dp/B07RPS2ZY3?ref=ppx_yo2ov_dt_b_product_details&th=1
Power LED: https://www.amazon.com/gp/product/B07TPLVXSP/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
The author remixed this model.
Added MK4 mount, reset button and power led.