1/2/21 - I added a new file with a thicker upper flange as the original is a little weak.
This is a remix of the one made by WachuTT. It is redesigned to allow air to pass through the vent around the gauge and will work with a "52mm" gauge. The opening is actually 54mm as the AutoMeter gauges I have pictures here needed that amount. I don't know if that was just those or not.
I also included an extra ring that allows the gauge to push forward further to be flush with the silver cover. I used two on each gauge so it is even and not set back. There is a deeper one which matches the original one by WachuTT but I ended up making a shorter one so I could use the adapter that came with the gauge to lock it onto it. You'll see what I mean once you purchase the gauges.
I recommend an epoxy to glue the silver cover to the 3d printed mount. I made mine out of ABS for the possible heat on a hot summer day in the car and it worked fine with a raft and supports. The supports are a bit of a pain to get off but not impossible and the finished product afterwards is worth it. Be careful though, the overhanging lip is thin and will crack. I broke one that way by pushing too hard when trying to remove the supports the first time.