This is my first project shared on here, so hopefully it helps someone out in the interwebs...

What we have here is, a functional print for a round style radio, large enough to replace a ma300 style radio. I threw this design together for my brother (his boat) and it looked cool. I attempted to print a tpu gasket for it, (file Included) however we opted to go with silicone to seal it instead. Use whatever you prefer to seal the surface mounting areas. Silicone worked just fine.

Printed in PetG for strength and durability in the elements, I went with cubic Subdivision for the infill at 10% with 4 top layers, and 3 wall layers, which printed really well.
No support needed as I designed it to lay flat.

The Center hole is 78mm in diameter to give the radio a millimeter clearance, and the screw holes are spaced to use the same holes from the old radio.
The new radio fits well with the hold down bar it came with (unfortunately I didn't get pictures)
Note: the thickness of this print had to be accounted for, by cutting/modifying the hold down bar that screws to the new radio. (U shaped bar held by 2 studs on the back of the radio chassis) The studs are about a quarter inch too short to use the nuts provided... [Insert joke here] LoL

Besides the modifications, it printed well and really looks good when it's done!
I truly hope this helps someone wanting to put a round radio in a hole that ended up being too big. ;)

(BTW I am no boat pilot, or professional designer, I'm just the cool brother that tinkers with the creative toys. :)