I found the same thing on my '90 300CE last week! You're right it is very flimsey. As a Mech. Engr. I was amazed. I welded it back together but I was tempted to weld some gussets on. I decided to wait and check with other owners.
First, how expensive is this piece to replace? Second, has there been any improvements? Third, has anybody welded on gussets?
I just don't want it to break again - whatever it takes.