I have a bin full of these old side-winders, also inherited. Two of them are B&D, one just like yours. I used to cherish them.
Then about 10 years ago someone gave me a brand new Bosch side-winder. I looked at it's all-plastic construction, said "no thanks", and kept using these older metal-bodied saws. Until one day there was some reason I pulled that new saw out to do a job, and after just one day of use, I fell in love with it. More power, less weight better guides, quicker adjustment, quicker stop... win-win-win. Now the old metal saws get relegated to destructive use, like sawing masonry or abrasive blade use.
There are many tools one could name as useful, the trouble most here already own and know them. So, for something a little less common, I bought a pistol-grip 1/4" air impact about 20 years ago, that has been a godsend for working on vintage equipment. This was back before lithium 1/4" impact drivers were common, and it had just the right amount of torque to hammer away at a rusted fastener without shearing the head off, until the fastener would eventually break loose. It was my go-to for anything larger than #6-32 and smaller than 3/8", for many years. If you don't have one, and you find yourself working on a lot of old hardware, consider it.