I would have to keep that one for a while myself. Are both hoops original or is one a replacement?
The top one is a replacement. Looks like a Hella (German company) diecast hoop up top. From Sonor they did not come with die cast hoops - or at least not in the catalog.
On that note I would like to mention that Sonor does not always offer kits from the catalog. A good point would be my Sonor Prolite kit which is not a cataloged yet 100% factory kit. In fact if you talk to any Sonor endorsers they will look at you puzzled if you mention cataloged setups.
I believe that it is from the mid to late 80's to be honest. The quality is out of this world. I would rather part with two or three other snares vs. this guy. In the context of rock or pop music it is the bees knees.
Manny