The first-generation bodies were engraved like that, even though the flashlights were classic 6P's in every way except the dropin.
There were two variants, one with a Nitrolon head/bezel assembly and one with the traditional Z44 aluminum assembly.
I think the Nitrolon 'Z44' variant came out a little later, but it's been a while & I'm not certain.
That was related to the poor performance of the thermal-limited P60LED dropin;
- 80 lumens upon turn-on
- ~60 lumens thermally-regulated in the aluminum Z44
- ~50 lumens thermally-regulated in the nitrolon 'Z44'
They were horrible dropins, and I got rid of mine as soon as possible.