looking for a sea&sea spare part

I was changing a leaky oring on my MDX-PRO MKIII tonight when i broke  the threaded part in which the axle of the boutton goes. In the red circle on the second picture.

Does anybody have an old housing which could be a donor for this part ? I think most of the mdx housing got this part.

Thank you

As the MDX-PRO MKIII is discontinued, your best bet may be to contact your local dealer or Sea&Sea for a replacement part. 
https://www.seaandsea.jp/contact/