Here's an old strainer with a Red Head NH fitting.  It's rusty on the bottom half inside and out.  I would guess that it got stored in a wet location just a little too long!  I peeled some of the flaking paint off so you could see the rust.  If you did a little sanding and got some paint, it may not be a bad back-up for you?  Please see the pics for condition - it's sold as-is...