Lot of 5 vintage aquarium air pumps - Metaframe Hush I Quiet I - Sternco -

Description

Lot of 5 vintage aquarium air pumps.  Sold in AS IS condition.
All pumps turn on and hum when plugged in but no air comes out of them.  I opened up the Metaframe Hush I pump and looked at the rubber diaphram and it didnt look like it had any cracks but did not have any replacement diaphrams to test.
I would assume that all these pumps probably need new diaphrams, they have been taken out of storage a couple of weeks ago but were wrapped in newspaper dated Sept 1975 so I would assume they have been stored since then.
May need other repairs that I am not aware of.