Anyone familiar with: Pickering

I'm trying to get information on a Pickering "Fluxvalve" Pickup (cartridge/stylus)model: 350DS. This Cart/shell assembly came in a plastic clear top case with 2 built-in styli holders (for lack of a better term)one holding a .001 Diamond stylus the other a .0027 Sapphire stylus(G) and a third stylus which I believe to be Diamond also already in the cartridge. (Probably from the previous owner. I'm looking for any information regarding this "Pickup" kit. i.e. what type of turntable it was or can be used with and so forth. I know it was purchased on Sept 20th 1956 from Newark Electric Co. in Chicago, ILL., because I have a pristine receipt for the sale! The "Pickup"/ stylus case came in a blue/gray/white Pickering & Co. box.
So, if this jogs anyones memories of having or seeing one being used I'd appreciate any information about it you'd care to submit.
Thank you very much. I appreciate all of the priceless wisdom, opinions and knowledge I find here on AudiogoN daily.

As I recall, Pickering made some rather fine cartridges in their day. I had one on an old Rek-o-Kut table some time ago. I beleive that one stylus (the diamond) was designed for 33 and 1/3 RPM usage, while the other was for 78 rpm records. You can inspect the stylus tips to see if they are appreciably worn with a good magnifying glass or binocular "macroscope?" (we used to use these in biology class). The tips should be rounded, and not to badly chiseled in appearance.
Pickering, of course, was the consumer twin to Stanton Electronics which is still, I believe, situated on Long Island NY.
Pickering was indeed the "consumer twin" to Stanton but alas, after the death of Walter O. Stanton the company was sold and moved to Florida, with much of the production now done outside the USA. Stanton, far from "professional" in the audiophile/transcription sense, now concentrates on the disco market. Their best line of cartridges, the 881S and its derivatives, has been discontinued and the current version of the very long-lived 680/681 series has styli that are more massive than those of olden days, as though the "audiophile" designs are now mere derivatives of the disco product.