This picture shows the hardware required to mount a coro prop to vertically installed siding. From left to right: 1/2" conduit hanger, washer, nut, bolt. Missing from the picture are 1/2" PVC electrical conduit, and large binder clips.
Drill a hole into the coro prop the exact width of the screw. From the front of the prop, insert a screw through the washer, into the drilled hole. On the back of the prop, secure the conduit hanger onto the bolt with a nut.
Cut off a 1 1/2" section of PVC, insert it into the hanger, and secure it with the bolt/nut.
Install two (or three if coro prop is heavy) large binder clips onto siding.
Rest the PVC onto the binder clip handle. Secure the coro prop to the binder clip handle using an 8" - 10" nylon cable tie. (Note: I didn't have the right length on hand, so used two smaller ties joined together for demonstration purposes only.)
Result: Coro prop is now securely attached to the siding.