Magnum 500 loose center caps repair advice needed

[Costa Q Code]

Hi All ! One of my center caps became loose where the metal round pronged tension bracket thing on the inside became separated from the cap itself

I am having a hard time getting it to stay back on properly, I tried soldering but it wouldn't stick, I tried JB Weld and it cracked while trying to snap onto the wheel, also tried super glue same thing again, so if anybody has any previous experience or ideas, would love to hear them

As you can see in the picture on the one on the right even with all that JB weld did not stay attached, the one on the left appears to have tiny screws holding the tension mounting bracket in place ? Maybe I have to use a piece of wood or rubber mallet to pound it evenly in place or bend the prongs in a bit to make it easier ?

Thanks in advance

 

[rvrtrash]

Hate to ask, but when you soldered, did you scuff the solder points, use paste flux to clean and then acid core solder, like you'd use for copper pipe?