1980 Datsun fuel pump

Hello:

attached, I think, is a picture of the 1980 Datsun fuel pump.

Hoping to get to get a definitive answer to what the attachment is that is in the location where a check valve is normally seen.

Some have said the attachment is a check valve others have said it is a fuel pulsation damper.

I'm hopeful that the attached picture will result in identifying the attachment.

Thanks to all for your patience.