m15 and m15a1 1/2 tracks

[pand65au]

is there anyone out there with acces to or diagrams / photos of the m54 combination mounts of these 1/2 tracks?? i have shedloads of pictures and books of the vehicle in service and preserved but what's behind the armoured turrent?? I have been only able to find 1 picture (left side view only of the 37mm m1) but not a clear diagram of the m54 combination mount with out the armour! I wish to scratch build a model of one of these to go with my m13, m16 and m15 special 1/2 tracks. is there anyone out ther that can help ?? here in aust these vehicles are a little thin on the ground.