Hi all,
Graham, glad to hear the O-Pac & Signature wing is working out well. We just returned from that trip to Fiji, and my wife dived the same combination there for 10 dives - we went with some cheap XS Scuba 5lb weight pockets, distributed as Rich mentioned, on the waist and camstraps - her trim worked out great. She left the back padding off the O-Pac as well. I lugged a backplate along.
There's some body position techniques you can use in the water to shift your "centre of buoyancy" and maintain horizontal trim, like extending or retracting your clasped hands in front of you (extend to go head up, retract to go head down), and bending your knees to raise your feet.
Stainless steel backplates - after a serious time gap, we've got them back in stock.
Kriterian,
There's no bolts for the O-Pac - a simple solution to holding the wing in place is some mouthpiece ties (aka zipties) through the pairs of grommets in the O-Pac and the wing (assuming you've got an OxyCheq wing). Pull them tight, and trim. Rock solid, and seeing as the weight of the tank is born by the camstraps passing through the O-Pac, there's only the minimal weight of the wing on them, so they're not a failure point.
Any other questions, feel free to post them here or in a PM.
cheers
Ben