Okay, let's add to the quandary on this thing.
I was digging in an old truck toolbox today and came across a surprise. Once I saw them, I remembered that my cub came with "extra parts" but didn't know it had these! So now I'm at a cross road... do I break apart the cub and install this creeper? I can't tell if everything I need is there or not, or if the driveshaft needs rebuilt (no teaser spring--are those required?), or if there's a way to test the creeper operation before putting it all back together again and finding out something's not working.
I've not ordered any parts yet, BTW.