Use a combination of pliers and this little bending tool. The wire doesn't have to fit exactly deep in to the outside groove.
This tool is to bend a round back for piece 2, make adjustments with pliers.
Begin with wire across center channel.
This spring steel can be a challenge to bend, use a firm grip.
Now the wire can fit around back side of cylinder.
Work with the tool left and right side of brace.
Make round and as tight as possible against the cylinder.
The wire doesn't have to fit exactly deep in to the outside groove. Use the pliers to make small bends for the fit in piece 2.
Cut a small strip of the fuzzy side of velcro. Wrap the end of the mount and zip tie.
Pull the zip tie tight so the velcro rises around the zip tie.
Probably a few more adjustments with pliers before the wire will press into place.