One version of the Busra Bunong font {Mo5V56Bu.ttf} is included on that page in the special variants download: Mondulkiri-5.300.zip. However, our Paratext project uses an updated version of the Busra Bunong font , which isn't publicly available yet. The file names are {BBV8-r.ttf, BBV8-i.ttf, BBV8-b.ttf, BBV8-bi.ttf}. May be it's too messy to include support for Busra Bunong. If that's the case, we don't mind if our text is displayed with the Khmer Busra font, but we're not planning on changing the default font in the Paratext project itself.