I claim the ornamental design for a speargun camera holder assembly, as shown and described.
FIG. 1 is a side view of the speargun camera holder assembly, showing the mounting plate, lanyard, and camera base;
FIG. 2 is a bottom view of the speargun camera holder assembly showing the mounting plate portion;
FIG. 3 is a top view of the speargun camera holder assembly showing the mounting plate, lanyard, and camera base; and,
FIG. 4 is a perspective view of the assembled speargun camera holder assembly on a speargun.
The broken lines shown in FIG. 4 are for purposes of illustrating environmental structure associated with the claimed design in condition of use, and which forms no part of the claimed design.