rare old metal toolbox w/ stair stepped skyscraper lid, worn vintage blue paint plumber's tool box

Unusual old metal toolbox with a wonderful early machine age look. This is probably early or mid 20th century, I think? Though it might be much older - I really couldn't find any information about a box with this shape. There's no makers marks or labels.

The interior has a metal bracket to hold a specialty tool of some sort, something fairly large judging from the size of this toolbox. It's about 10 1/2" tall to the top of the lid, measures about 15 1/2" x 8" over the bottom (exterior) of the box.

Box is pretty clean overall, inside and out. Solid brass handle looks to be original. BUT - this has a large saw cut to the lid only, at the back corner. I feel like a little careful filing might be a good idea, if you don't decide to give this piece a good welded repair.