How to describe this Parker Duofold cap?

[radrav]

Something, perhaps glue (no idea how), has interfered with the threads and made it impossible to use this Parker Duofold fountain pen cap and  I understand that it cannot be repaired.  Can you help me describe it accurately so that I can search for a replacement?  Also, if you know where I might find a replacement that would be helpful. You may contact me directly <rad2556@gmail.com>. Thank you.

Edited December 20, 2020 by radrav

[FarmBoy]

Looks like a Jasper Red Duofold.

 

There are two sizes. International and Centennial. 
 

Repair is likely a better option than replacement.