Essentially that, Grease Gunner.
Keep in mind they were imported long before the '68GCA came be codified in the CFR.
If it was compliant at the time, it is exempt if kept in the original configuration: no modifications or additions.
Interestingly, the trigger housing on this specimen is actually from the '62 MK series G3's, as the word Pasadena is missing.
It is present on the 10B series HK41's.
In today's world, it is humorous that the guns are older than most of the ATF agents, so most have never even seen one in the wild.
S u b R o s a