Service Bulletin but not for the RS?

[ESquared]

Checked with a RS owner on this forum who’s bike was built the same week and his has the hole and valve.

That would be me.  

Here's the pic of the duckbill valve from below.  Upon original inspection, it was just kind of "floating" in the hole, so I used a tiny set of needle-nosed pliers to gently pull it down/out until it was seated properly.  It will bear keeping an eye on, as it doesn't seem like it would take much to  move it out of position again.  If not firmly in place, it sort of defeats the purpose, as all you're left with is about a 7mm diameter hole in the bottom of the swing arm, open to dirt, mud, water, whatever.