1:100 Macross (Frontier) VF-25F 'Messiah' - WiP
The kit comes with a clear display, that features a kind of bracket for the underbelly gun.
However, I will use my home-made standard display for Valkyries in flight. It uses a thin iron wire as holder, much less visible, and it is mounted in a weighted (lead band) base from a vintage ARII 1:100 Valkyrie Fighter display.
In order to mount it to the VF-25, a 3mm hole was simply drilled through the gun into the lower fuselage - this should suffice and work well.