Far too lean 604-8Gs in 620 kabs

[speakerdave]

Just removed the Altecs 604s and removed som fiberglass from 2 sides in each speaker. Initial impression: more open/transparent or lively sound. The bass membranes are stamped 1803035662 and 1803035(5or6) cannot se last two figures.
Does this indicate original membranes or later recones?
Regards
Kjartan

If anyone responded to this I missed it. Those are not Altec cone numbers for the 515b/604G, so they are apparently recones. I don't recognize the numbers, so i cannot place the source.