Baron: Yes, it's the Tamiya kit. I have all three Yorktown class, and they are identical to each other, with the exception of some different sprues/parts to distinguish between them. Mainly these seem to be in the types of catwalks around the flight deck.
I didn't have them "back in the day," when they were first released in the '70's, so I don't know if they updated anything at all. I haven't researched Hornet yet (except to find that the flight deck is not correctly shaped), but I can say that Enterprise's parts (catwalks, some gun tubs, etc.) are not accurate to any specific fit, and not very close to the Midway era at all.
Yorktown is also inaccurate for some of the weapons placements. Tamiya gave her too many 20mm positions (where she didn't have any) and no .50 caliber positions at all--when she apparently went to Midway with some 24.
Enterprise and Yorktown also had gun tubs for .50's off each side of the forward flight deck, and Tamiya did not include these.
There also seems to be no difference in any of the kits' island structures, although each ship in the class was somewhat different.
I had to kit-bash a Hornet and an Enterprise, according to Gordon Bjorklund's research on the warship forum, in order to get a reasonable Midway-era Enterprise.
I remember when Yorktown was released a couple of years ago, there was disappointment among ship builders that Tamiya had not re-tooled anything.
Even the aircraft provided were pretty primitive, so I've been using Trumpeter's versions. Trumpeter's are clear-molded.
Still, the ships look pretty sharp when finished.