Gravy dish! Vintage Made in Guadalajara Mexico

Gravy pouring bowl by Lofisa ! Made in Guadalajara Mexico Classic/ Retro/ Vintage This has been in storage. My friend bought it/ she was selling vintage collectables. I took over but this hasn't seen light/usage in at least 7 yrs. I washed/ There's 1 rust-looking streak/line on 1 side. Not sure...it may come off with bleach or ??? I haven't tried yet. See pic. No chips! I'm actually considering keeping/gifting this. Beautiful blue w/yellow flower &green leaves design. Used. Ceramic. #gravy