Just Joined...Rear Tailgate Shock Issue

I figured there has to be a Trailblazer forum, I'm on about 4 other forums all they are all great! I have a '03 and my left rear tailgate shock lost it's oil. This is Not heavily used, this shouldn't happen on a '03... Can't find aftermarket, Chevy want's $29 each (also right & left are different go figure). Does anybody have the part numbers (not for the glass shock)?