"Fabricator Ed" wrote: " if you know what a working Autopulse sounds like, you’ll know that ain’t them."
Well, yeah, but you've already (wisely) bought that Carter-style rotary pump. You could have bought a couple (1 in series for redundancy) Facet clicky-clack pumps that would have made the same clicking racket that the originals did!
Then you would need a really loud exhaust to be heard over the noise of the Facets...