I was reading over the users manual for my P226.  The parts diagrams feature models without target sights. The P226 X5 has a manual features a diagram with the rear target sight as a single component / assembly.

I'm looking to replace what I believe is a "spring" or "screw" missing from the rear target sight assembly.  It's best to illustrate:

When I bought the unit, the dealer told me to buy some Tetra "blue" solvent to help seal it in place.

http://digitalfreaks.org/~lavalamp/cp/displayimage.php?album=6&pos=49

http://digitalfreaks.org/~lavalamp/cp/displayimage.php?album=6&pos=50

http://digitalfreaks.org/~lavalamp/cp/displayimage.php?album=6&pos=51

http://digitalfreaks.org/~lavalamp/cp/displayimage.php?album=6&pos=52

http://digitalfreaks.org/~lavalamp/cp/displayimage.php?album=6&pos=53

As seen here, missing on the right when facing into the barrel.  On the left looking down wind.

Can someone tell me what the designation for these two screw/spring/threaded items are and what function they serve?

Also, what are my options? Find a dealer when the gun show comes to down?  Buy a whole new rear site assembly?

TIA
~BAS