This is an old tool and does have rust.  It was used by a home builder then sat on a shelf for several years. The screw does turn and the blade looks like it could be sharpened

Marked as made by Stanley on the blade area

The piece would definitely need a heavy cleaning.

I did move the blade back to prevent damage during shipping.

The bottom of the blade looks like someone tried to clean it but it left marks

The piece is 14 inches long, 5 1/5 inches tall, 2 3/8 inches wide

This item is heavy.

Leave near Denver?  Local pickup is available.