Mortal Kombat Wall Hanger , dimensions: 297.50 x 297.50 x 79.45mm or 11.71 x 11.71 x 3.12in
Scale up or down as needed, however the outer is ring only like .25in or 6.35mm thick so keep an eye on you minimum tolerances if you scale it down...
File is 2 pieces, both 250k poly.
I left some room in between the parts to allow easy installation but, you may need to do a little sanding on the edges.
This was designed specifically for FDM/FFF printing though, its possible to resin print this you just may need to do a little modification.
If you need any help with the file let me know.