Found this in the trunk of a 40 Ford I'm parting out. It is bolted to an oil fill tube with a crudely made bracket. I guessing fuel pump, but that's a guess.
Looks like there is a diaphragm on it maybe just maybe it's a sw fuel pump or a float for an early sw electric fuel pump.
Commonly available Stewart Warner electric fuel pump from the '50s,'60s & '70s , although a strange place to mount it as they were "pusher" pumps, & not nearly so good when used as "puller" pumps
It's a Model "A110" Stewart Warner Fuel pump...Very common before the "240" pump used in the OT late 60's race cars .... WOW...I type slow .....