Thanks to the above posters for there help!

Answering my own question for VAT refund at SVQ;

No line , very hard to find.

From the departures floor/check in, take the elevator gown to the arrivals floor. Walk to the end of that area to where there are folks waiting at the closed doors for people to exit the luggage pick up area.

In the corner, there is a phone. Call the number listed in the sign for Civil Guardia. Tell them “Tax Refund”.

Go through the doors (they will open for you hopefully); you should see a Civil Guardia officer opposite you all the way across the luggage area (I.e. past the carousels). She was looking out for us and signaled to come over. Be prepared to show your things - we had to unwrap one partially- luckily the bubble wrap was see through.

According to her, no stamp on the form was needed, but we mailed in the form anyway.

Not sure how I figured this out early in the AM. Took about 20 minutes including finding the place (no one else in line).