Kinda bizarre.
Got back yesterday from a 30+ mile ride and heard a "clunk" as I pulled into the garage. One of the acorn nuts for a top shock bolt fell off! Checked the other side and it was history. I expect someone got it through their grill. My own fault for not tightening them properly. Lesson learned.
Learned another thing...
IPB shows the bolts as:
PN 170399 Hex Bolt - 3/8"x45 (for RH Side only), and
PN 111696 Hex Bolt - 3/8" BSF x 2" (For LH Side only).
Ok, I "get" the 3/8" diameter (M10 replacement is too big to fit). What I've
never seen is any SAE diameter mixed with a metric length (45mm) and metric thread pitch (1.25 as measured with my pitch gage).
So I took it to ACE hardware to mess with the "pros" a bit. Had a bit of fun with them scratching their heads and telling me "No way!" "Impossible!" "Where the hell did you get this?!?"
A couple of 3/8" x 2" bolts with matching Acorn nuts did the trick for me, and I ordered a couple each of the OEM bolts and nuts for good measure. I'll keep them in my tool bag.
Went home. Finished installing my now primed and painted mounting stays for the RE Pannier racks, and short of a chain and oil change in a week or two I'm good to go!