I smirked at your notion that once a card looks like Woodcutter+, it appears boring^^ Also I've never thought of Goons as a Woodcutter variant (just joking here).
Now Bookkeeper has a lot of double letters in its name offers an interesting attack concept and seems solid as it is. But what do you think about other options such as either top-deck a Copper from your hand or gain a Copper, like popsofctown suggested? Also, as a vanilla bonus, what about +2 Cards? That seems reasonable to me, too. I don't know how much you are falling for your current version but I'd suggest trying different things and see what's actually the most fun.
I assume Bookkeeper is intended to be an addition to Enterprise in which it would fit nicely since it "cares about Treasures", especially Copper, allowing some exciting interactions with Clerk, Mill Town, etc.