Used Colt CM marked SP1 upper. Comes with ejection port cover and rear sight installed as well as a charging handle.
$175 via USPS money order or discrete form of popular online PAYment, PAL plus 3.5%. Email, no IMs.
SPF to AFJRTCTM
The only trade I'm actively looking for would be a nitride or nickel boron BCG but let me know what you've got.