Did ammonia drop to zero as well? If so...it looks like you're cycled!!!
Even though your no3 is low enough, I'd still do a large water change to restore minerals / buffers in your water before adding fish.
If the tank truly is cycled (which it appears) I'd go ahead and move your other fish into this one. That way you can finish your other tank by basically continuing that one as a fishless cycle while the fish are moved to a safe place.
The only thing that scares me a bit was that odd nitrIte reading you got. However, if it seems stable now...I'd personally move over the other fish. Good job