Translation: It is almost done that only needs one more signature.

Or: It is almost complete that only needs one more signature.

It is almost done. ..

This is almost done/complete/ok..

Use the word complete to describe "finished"/"well", it is also possible,

But when using complete, remember to add the verb be be after it, because there must be the verb be before the adjective.

That is, it is almost complete...

But if it is a more colloquial translation,

I would say: It'll be complete if we just got one more signature.

Or: It 'll be complete if I just got one more signature.

Whether you use we or I depends on whether the signature you need is one you need to collect, or one that everyone needs to collect.

If you don't pay attention to who needs this signature, it's simpler, then

It'll be complete getting one more signature.

Actually, I don't know you Say...whatever, it will be good. What does "just good" mean?

If you want to express, "Now there is only one person's signature left, and it will be perfect."

Then just replace done or complete with perfect.