Da-lite Silver-lite manual projector screen: Repair help!

So today I totally scored at Goodwill with not one but TWO projector screens!  One is your typical matte white but the other is a silver screen by Da-lite!  (well, both are da-lite) And I was DALITEd (see what I did there?) to find them so cheaply!  So purchased them I did.  But getting home I discovered the silver screen projector (the case a beautiful teal color!) had some rips.  Luckily not across the main viewing portion but along the rails that A-roll it up and B-keep it from going into the case.  I managed to fix the tears along B but A I'm aware has some sort of tension spring dohickey that is only kept wound by the end caps!  And to fix that tear I'll definitely have to completely disassemble the thing.  (to fix the tears I've used a combination of hand sewing and shoe-goo on the underside, since it repairs vinyl.)

I can't quite find a repair/replace/fix guide that even comes close.  I was hoping to come across a guide replacing the material at least but that was a no-go.  Closest thing I found was to carefully take off the ends and with the screen rolled up screw back one end (left) and wind the rod back with the other (right) before screwing it back in.  Guide didn't really specify my model though or even go into detail about the specific tension mechanism, so I'm doubtful at best on wanting to try it out. (and heaven forbid lose a finger!)  Not to mention mine pulls up instead of pulls down, so orientation seems like a toss up.

Anyone have any suggestions for a DIY approach to this?