I can tell the difference between male/female cats, but trying to figure out which calipers are L/R has me

brake bleeder valve will be on the top side/upper end of the caliper when mounted on the car (so air cannot be trapped in the caliper if bleeder was lower), however, i've heard some 914 calipers have 2 bleeder valves. also, on rears, parking brake lever is on bottom/

Rears: Put them in front of you with the back of the caliper facing you. Put the two handbrake arms together. You now have them left and right.

Fronts: Depends on the year but... go through the same exercise. This time put the bleeders on the "outside" edges. You now have them left and right. If they are dual bleeder models, look for the bleeder that is indented further into a round cutout. Put those on the outside edges. You now have them left and right.

Front calipers for the 914 should have pistons with a section of the face, that touches the pads, recessed. The recessed portion goes up, or more specifically the cut edge faces the direction of the rotor turning to meet it. Thus the leading edge of the pad is not fully supported by the piston. Generally this cutout is at a 20º angle and there is a sheet metal keeper to prevent the piston from rotating. This keeper is held in place by the upper pin.