I think if it has the 80 prefix then it is a Series 80 gun.
You can tell for sure by locking the slide back and turning the gun over to see the firing pin block plunger next to the disconnector cut.
I know that "Series 70" has become Internet Shorthand for "lacking a firing pin block" but from 1970-1983 it had the specific trademarked meaning of a Colt Government model with the Acurizor collet type bushing. So there is no such thing as a Series 70 Commander because they never used the collet bushing. Guns made in that period still had 70 prefix serial numbers, which tends to confuse people.
If you yearn to know the year of manufacture, call Colt; they will tell you that but no more without paying for a factory letter.