threaded collars for struts

[Mark Andy <mark@sccaprepared.com>]

Howdy,

Does anyone have a source for the standard threaded collars for struts?  
I've got some threaded collars I picked up as part of a coil over/strut 
package (for a BMW 325is... Sorry!  :-) that are cracked and need to be 
replaced.  I was hoping to just be able to buy a 12" or so section of 
threaded collar and use that...  These struts have a welded on perch the 
collar rests on.

Anyone know?

Thanks!

Mark