Thanks on the bug Page- but if you have this issue here is how we fixed it:
nothing lua involved. You only have to swap out the .edm files, which is the 3D model.
The correct path would be:
\DCS World OpenBeta\CoreMods\aircraft\MiG-21bis\Shapes\R-3R.edm (or S)
to
\DCS World OpenBeta\Bazar\World\Shapes\r-3r.edm (or s)
Or at least I hope this would fix it.
\
Thanks!