Or you could skip the mold and just wrap the fiberglass cloth over the packing tape, pull it taut along the trailing edge and fiberglass it. If you were making multiple copies a mold might be worth the effort.
OTOH, if you have more EPS you might recut those. The 0.08 cross-section has a maximum thickness greater than the tubing diameter, and a full half-circular cutout. Your pieces have the center in contact while the tips stand proud. Or you could add wedge shaped strips to fill the gap.