These are the bayonets he is talking about:
UNCUT
Bayonet, M1 with M7 fiberglass scabbard. It has a 10-inch blade. The fuller was 5.75-inches long and began 3-inches from the point. The blade tip ended in a spear point and plastic grips, black or brownish in color, were installed. Production of this bayonet type began in mid-1943 during World War II (as mentioned above).
CUT DOWNS
Bayonet, M1905E1 with M7 fiberglass scabbard Between 1944 and 1946 the US Govt modified many of the earlier 16-inch M1905 Type 1 and Type 2 bayonets by cutting the blades to 10-inch length and regrinding the tips to either spear or clip points. They're easily ID'd since the blood groove runs out past the blade tip. There is some evidence to support the claim that once these essentially World War I vintage bayonets were modified to the 10-inch blade length they became mixed with the Bayonet, M1 in the US Govt logistical supply system of the day and were also called Bayonet, M1. Technically this was incorrect as the official designation is M1905E1. Many of the 16-inch M3 scabbards that matched the 16-inch M1905 bayonets were modified to accept the shorter 10-inch M1 and M1905E1 bayonets.
The M5 series is a later Korean Era M1 bayonet. I have two M1 blades, an AFH and Greek Army copy. Not CMP purchases.
Wait to see quality. Better grades may come out and would be better spent as market value on nice one's is around $125.