<<<I know that years ago there was a pump (whiting?) that was
developed that actually had more of a mechanical action in
pumping>>>

Sounds like the Whittleston (??) pump from New Zealand.  I don't know
whether they are still made, but they were unique and had a good
reputation.  I think they were inspired by the dairy industry. Any
Kiwis on line??

Ros Escott
Tasmania, Australia
Going to NZ next week for the NZLCA Conference.