This is a Threaded Rivet Tool ( also sometimes called a Rivet Nut tool). made by Marson Corporation. American Made. It is used in connecting various fabrication to welded metal. In this case it was my campervan conversion. It has 6-32, 8-32, 10-32 and 10-24 1/4-20 and 5/16 threaded rivets and the tools to squeeze these rivets into holes, enabling screwing into sheet metal in vehicles, tool boxes, cabinets or what ever you have.
I used this for hundreds of connections to the body of my Ford Transit Van.
Great tool in good shape.
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