Readership,
I have an older, cast_iron mitre box , and Diston back_saw.
The box has a rite & left hand slots, 1/2" width +\- , running thru the horizontal bed, up to the verticle back fence, and thence continueing 'up' slightly into this verticle fence.
I can SWAG that these 'slots' are for some sort of work_piece hold_downs .
Googled a bit , but no hint of what these 'slots' hold ... clamp/hold_down/???.
Anyone know ??? A URL pointer ???
Ed