Piece of Brass w Patent Dates

[cambria09]

Howdy All. Found this item at a 1900's home site. Need Pat Date help: FEB 20 72; SEPT 24 72; MAY ? 81; MAY 24 81.

Is there some way to search this by the dates?

Thanks for the view and and any info, good luck tomorrow. C9

 

[lockster99]

Looks sewing machine related to me.