I know this topic (i.e. compiling 2203 equivalents from assorted factory and aftermarket parts due to JBL cone kits no longer being available) has been discussed in multiple threads, but I can't find any clear conclusions/solutions.

The main obstacle seems to be finding spiders with the correct compliance. (Donors for baskets and cone/VC assemblies are plentiful, mass rings can still be ordered, and appropriate aftermarket foam is available - correct me if I'm wrong.) It has been proposed to cut stiffer spiders to losen them up, but according to the expertise this is a questionable method WRT durability. Another proposal was to search for aftermarket spiders. Did anyone have success here?

It would be very nice if we could arrive at a BOM here (and possibly some hints for DIY:ers who are brave enough to attempt such major surgery...).

(Background: While searching high and low for another 2311 for my Baby S22 project, I by chance found a reconer who claims to have spiders for 2203/2231. "I have it. I'm the only one who has it!" Of course I'll follow up this lead but I wonder what it could be - aftermarket stuff or NOS? Did JBL ever sell this item separately? Could he possibly have bought parts directly from the OEM plant?)