no idea

[Stegner]

Material seems to be brass. The eyelet suggests this either was a hanging item or it was part of a mechanical device. By the large bottom opening the edge is scalloped which would suggest ornamental design, but there are areas on the sides that are rough-filed which would suggest its not ornamental. The inner pin is not flexible and sticks out of the exact center of the internal cavity. Help!

 

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[mojjax]

maybe of an old fashion hand pump . The area between the two raised rings may have had a leather washer . Just my guess .

 

[Ant]

My guess is the innards of a vacuum actuator of some sort:
https://images.search.yahoo.com/search/images;_ylt=AwrTcXTVxCpVr0QAekOInIlQ;_ylu=X3oDMTBsZ29xY3ZzBHNlYwNzZWFyY2gEc2xrA2J1dHRvbg--;_ylc=X1MDMTM1MTE5NTc4NARfcgMyBGJjawNmNzRsbmpkYWdsMDFwJTI2YiUzRDMlMjZzJTNEaDcEZnIDBGdwcmlkA2ZOUURqUzA5UXhTSFR6WnVPWWNId0EEbXRlc3RpZANudWxsBG5fc3VnZwMwBG9yaWdpbgNpbWFnZXMuc2VhcmNoLnlhaG9vLmNvbQRwb3MDMARwcXN0cgMEcHFzdHJsAwRxc3RybAMyMwRxdWVyeQNhbnRpcXVlIHZhY3V1bSBhY3R1YXRvcgR0X3N0bXADMTQyODg2NjMxNgR2dGVzdGlkA251bGw-?gprid=fNQDjS09QxSHTzZuOYcHwA&pvid=iVqUgTIwNi7zkrebVQqAOQUANjYuMgAAAADZ628n&p=antique+vacuum+actuator&fr=&fr2=sb-top-images.search.yahoo.com&ei=UTF-8&n=60&x=wrt

 

[trdking]

My guess is the innards of a vacuum actuator of some sort:
https://images.search.yahoo.com/search/images;_ylt=AwrTcXTVxCpVr0QAekOInIlQ;_ylu=X3oDMTBsZ29xY3ZzBHNlYwNzZWFyY2gEc2xrA2J1dHRvbg--;_ylc=X1MDMTM1MTE5NTc4NARfcgMyBGJjawNmNzRsbmpkYWdsMDFwJTI2YiUzRDMlMjZzJTNEaDcEZnIDBGdwcmlkA2ZOUURqUzA5UXhTSFR6WnVPWWNId0EEbXRlc3RpZANudWxsBG5fc3VnZwMwBG9yaWdpbgNpbWFnZXMuc2VhcmNoLnlhaG9vLmNvbQRwb3MDMARwcXN0cgMEcHFzdHJsAwRxc3RybAMyMwRxdWVyeQNhbnRpcXVlIHZhY3V1bSBhY3R1YXRvcgR0X3N0bXADMTQyODg2NjMxNgR2dGVzdGlkA251bGw-?gprid=fNQDjS09QxSHTzZuOYcHwA&pvid=iVqUgTIwNi7zkrebVQqAOQUANjYuMgAAAADZ628n&p=antique+vacuum+actuator&fr=&fr2=sb-top-images.search.yahoo.com&ei=UTF-8&n=60&x=wrt

I like it!