Art, I'm honored.

Yes, the first photo in the original post is of an aftermarket part I found on the web when looking for a replacement to my original (last photo in OP) that has the failed springs. I haven't had one in hand so I can't comment on their construction but they definitely look different from the original. 

Re drawing...
For comparison, here is the 5DRS diagram from the same volvo parts catalog I got the 4DRS diagram.




Re price...
There are a number of ebay sellers offering the aftermarket sedan version for $17 - $20 ea. One seller had a pair for $29. Neither of my go-to online parts suppliers carry the tag lamp at this time. 

Finally, some thoughts on another potential solution...
Now if I only had some spring steel, here is a rough diagram of a solution that may work with the original CIBIE housing. Pros - just break off the exposed rusted spring w/ no need to remove the original bard in the mold and snap the new spring into the existing voids in the housing. Cons - need to custom build this spring.



Be well,
Ihor