You can find the Luth-AR A1 Upper Receiver Assembled here. Fast $9.95 shipping! Orders over $200 ship for free!
The Luth-AR Assembled A1 Upper Receiver is made from 7075-T6 aluminum forgings with correct early-style carry handle contours with A1-pattern rear sight. Includes the installed A1 Rear Sight, Ejection Port Cover Door and Teardrop Forward Assist. All points where other parts attach are finished current mil-spec dimensions. Current production AR-15 components will fit perfectly. Made in the USA. Note that the A1 Upper Receiver is period-accurate therefore it DOES NOT have M4-type feed ramps found on most current-production AR-15 flattop upper receivers.