I pray I haven’t overlooked a thread that covers this already. If so, please forgive me. I was hoping somebody knew what this attachment on this craftsman 100 (I think) DP is for.
That would be a mortising attachment on the quill and the work fence/hold-down on the table. It doesn't look King-Seeley/Craftsman or Atlas/Craftsman to me.
The arbor thing on the small board looks home made, I dunno.
Depending on its age, that could technically be a 13-1/2" Craftsman 100 if made before 1950. It is more commonly referred to as a 13-1/2" Craftsman 80. The head trim panel is missing, so that indicates it could be a '52-'53 model.