Who else is using old cables/interconnects, and is happy?

Oh yes, old stuff all throughout. 

Speakers : Straight Wire 'Waveguide' (using FuruTech spade and 30° angled screw tight banana type connectors).

Pre- to Poweramp : OLD versions of XLR Transparent MusicLink Ultra. 

LP to phono boards in Preamp : Vd Hul silver (something or other), 1,2 meters. 

CDP to Preamp : some old odd German brand low Oxygen type, 1' long only, XLR interconnects. 

CDP to DAC : OLD Transparent Reference, 2' long. 

DAC to Preamp : Some German brand, stock standard microphone XLR cables. 

Tried many, many alternatives but always preferred the lot mentioned above. 

I do concede that my system is just not sufficient Hi-End enough to make any noteworthy difference with more expensive / exotic type of interconnects and speaker cables. 😉
(also see my system page) 
Michélle 🇿🇦 

I also use Clear Day solid core solid silver speaker cables on the second rig. Took a few months to break in and open up fully. Bought them a few years before Paul passed away.

Phono cables are default Jelco JAC501. They seem fine. Better than an Audio Sensibilty cable I tried.
Interconnects are interesting. I’ve tried a few options with the best of intentions. While they all have had some nice aspects to the sound, they’ve all been colored in some way or another. So my trusty cheap ICs (not patch cords!) remain my reference for maximum detail. I use them for all non-phono connections in all systems.

Cables don't wear out so use them if compatible with new system.  

In my case, new speakers more neutral than old.   Old cables too lean and had to replace them.

Used StraightWire Maestro ICs and Kimber 8TC speaker cables for 25 years, but decided several years ago to give Cardas ICs and SCs a try. Liked the Litz/solid-core construction and the fact that they're made in the U.S. First time I've ever had the same manufacturer on all audio cables and I really like the results. Nice tonal balance and very musical.