The Best & Rarest of all Stereo Gear

i owned a pair of the large Nestorovic 5as speakers which you could consider rare. They weren't perfect but they were great in some ways and I really enjoyed my time with them.
I still own a pair of Celestion Kingstons which are also sort of rare and also very good.

I agree that it is a little more added fun to own an unusual component.
I forgot...I also own an Audio Note Kit One integrated 300B amp which is by no means rare, but mine is the 10th Anniversary edition with the dual c-core transformers, which not too many people order. 

Anyone ever own the Streets Electronic 950 amp or a Wingate amp?  Those looked awesome.  I once heard a Wingate at a high end show, but the rep was this young kid who believed everyone wanted to hear it at ear splitting levels and wouldn't turn it down.  Right now, I'm kind of digging on these rare 70's-80's turntables, maybe not so rare, just old :)

I have the very rare Biotronics Control Systems Gestalt phono preamplifier. I challenge someone to find information on it. It has some sort of active variable bass control and sounds very smooth. The board traces are heavy and appear plated with silver. It is obvious the unit (with its outboard power supply) was designed for the serious listener.

I suppose much of what I currently run is rare and quite nice sounding.  My preamp is custom-made by Aldo D'Urso in Italy.  This makes it "modern," although very few of the components are actually modern.  The chassis, tube (310 and 311s), input and output transformers, all of the resistors and capacitors and the Daven attenuators for balance are all quite old and repurposed; the only thing new is the remotely controlled volume pot and the power transformer in the separate power supply.  My amp, also built by Aldo, is essentially a stereo version of the Western Electric 133 amp--348 input/driver tubes, 349 output tubes, the correct Western Electric input and output transformers, vintage caps and resistors, etc; the only part that is new is the power transformer.

My speakers were made by Strumenti Acustici Precisione, but, I replaced the midrange horn with a circa 1939 Western Electric 713b compression driver and a Western Electric horn (the replacement midrange is free standing on the top of the bass driver cabinet, just like the horn it replaces).   The WE 713b is a terrific midrange driver, but, it is now VERY hard to obtain a matched pair of these things.

The rest of the system is more modern and still in production, although the Viva Fono phono preamp is not a common item.

All interconnects made by Confirmation Bias Cable Co. are the absolute best!  

While terribly expensive, they work like magic on the psychoacoustics of the ear-brain interaction.