It's one of the 'Post Burhoe, post inverted tweeter' EPI's. Since the most noted thing about the early EPI's was the inverted tweeter, it would be interesting to replace the dome tweeter with the older tweeter (probably from the 'A' series). The EPI A300 appears to use the same drivers as the TE320 except for the tweeter in a different cabinet according to the Human Speaker website.
While I own several EPI's and Genesis models with the inverted tweeter, I have none from the later period so can't comment on their sound quality. I would be curious if any AK'er has made that switch to the older tweeter since I assume (hope) the woofer was an upgrade. Was there was an improvement in sound?