BC-04 GoBuster Beet. Crane vehicle mode to Kabuto beetle mode, and then the mecha mode (much like GoBuster Ace)
SJ-05 Stag Beetle. Only two main modes, Jet and Stag Beetle. It can combine with Gobuster Beet to form Buster Hercules. Stag Beetle can also combine with GoBuster Ace.
FS-0 Ofrog. It can be attached to GoBuster Oh, replacing RH-03 Rabbit. Purely an auxiliary mecha.
Gobuster Oh + Buster Hercules =
GREAT GOBUSTER OH!!!
Goddamnit, this is Engine-Oh G9 all over again!!!