M7 Bayonets made for Colt.
Universal Industries
First Colt M7 bayonets were made by Universal Industries in 1961-62, about 20.000 were made. Green plastic handle.
Two variations:
-Colts PT FA MFG.CO HARTFORD CT USA (poss. prototype?)
-Colt's 62082 LOGO Armalite
Imperial 
Imperial made 30.000 Colt M7's. Blade is marked by a circle with a horse inside and Colt's 62316 Hartford, Conn. U.S.A. next to it. U.S. M7 marked under handle. Guard is marked only US M7, scabbard is M8A1 w/o maker markings, but crinkled surface.
Milpar
Milpar made unknown number of Colt bayonets. Scabbards were standard M8A1's.
German made M7 Colt-bayonets
The early Colt contract Eickhorn's M7's from 1975-76 are the ones with the standard 2 piece handle held on with two screws of which approximately 80,000 were produced.
Half crossguard Colt marked M7's were made to fit the M-16, G3, and HK33 rifles. They were first military issue and when Eickhorn fell on hard times produced commercial versions from stock materials for the collector market. Two blade variations: straight and curved. With and without the text "Made in W-Germany"
Blade cut is straight as in USGI standards.
Logo & text, 2 screw handle
With the text "Made in W-Germany"



Logo & text, one piece handle
With the text "Made in W-Germany"


Colt logo and "Made in Germany" etched to blade.


Logo and text etched, one piece handle.
Final model is a one piece handle version (with XX thru handle),"COLT'S 62316 HARTFORD CONN USA" etched, not stamped, on the blade. No markings on guard.
This was likely produced around 2000-01 right before Eickhorn's last bankruptcy, for collectors.