The powered Filing Attachment - a remarkable Pratt & Whitney accessory and probably unique to a small number of fine-quality American Precision Bench Lathe manufacturers.
Those who have used a "filing machines" will know that they are not what, to the layman, they might seem: a rough and ready method of removing metal, but precisely the opposite. A top-class filing machine was an expensive item - and an experienced operator could achieve almost miraculously accurate results with one. They were not designed to be employed in general workshops but found a valuable niche in better-equipped toolrooms.
The Pratt & Whitney unit slid onto the bed and was fastened in position by an eccentric clamp. A tilting rectangular table 4" x 6" was fitted as standard.