
eddiephlash |

The Pre-core version has a base use of Str/Melee + 1d6 + 2 and the Curse version has a base use of Str/Acro/Melee + 1d6 + 2, so it seems they are both a "+2" weapon.
The remaining powers are similar though not exactly equivalent:
For your combat check, reveal this card to use your Strength or Melee skill + 1d6+2; you may additionally discard this card to add another 1d8 plus the scenario's adventure deck number. If not proficient with weapons, the difficulty of this check is increased by 4. If you succeed at your first check to defeat a bane that requires sequential checks to defeat, the difficulty of checks to defeat during this encounter is decreased by 5.
For your combat check, reveal to use Strength, Acrobatics, or Melee + 1d6+2; if this is not the first combat check to defeat the bane this encounter, add 1d8. If proficient, you may additionally discard to add another 1d8+#.
I'm playing (Curse) Varian in a card guild campaign, who would greatly benefit from being able to use Acrobatics with the Sawtooth Saber from Curse via the replacement rule (when I get there in a couple adventures).
I know the rule as currently written forbids this, but I wonder if the name of the Curse version of the card was an oversight? I also wonder if there are other cards where the names are nearly the same that might at least qualify for a review or discussion.

Yewstance |

No. Whilst I can't find the exact thread at this point in time, it was specifically asked of Vic somewhere on these forums where cards with the same name but a "+1" or "+2" appended to the end could be replaced or not, and the answer was a hard "No".
Seeking Shortbow also falls prey to this issue (though the pre-Core and post-Core Seeking Shortbows are very different levels, which somewhat proves the point that they shouldn't be replaceable), but to ignore "+"s would mean that you could replace a Longsword +2 with a Longsword (Core) as another example of how it could demean the intent of the replacement rule.
Post-Core characters relying on Acrobatics weapons (unless they're using very specific Class Decks) are going to have difficulty finding them in the later half of adventures, unfortunately. Just something we'll have to carry until new Class Decks are released.