Ground Instructor Test

I hold a Subpart H instructor rating in one cat/class with
Subpart K (sport) instructor privileges in a second
cat/class. I've been asked to give ground instruction
towards a rating in the second cat/class. I know I can give
the written signoff for a sport applicant to take a sport
written in the second cat class. However, I figure I might
as well get a ground instructor rating and be able to give
the signoff for Private as well as Sport.

Questions:

1) Is there a sport knowledge test out yet? When I looked
at this a while ago they hadn't written one.

2) Do I need any signoff for the GI or AGI test? IIRC, I
can just walk in and take it.

3) Anyone know the fee for these tests?

Thanks.