Hi Simon. Welcome to AOS.
You were lucky inheriting all that nice vintage gear. That would have been a cutting edge system 55 years ago and is still desirable equipment. You could feature it all in our 'Past Masters' section with some photos, it would be nice to see. The Quad II power amps, Decca cartridge and IIILZ speakers are sought after items. The Tannoys by the way are not single coil, they are two drivers in one with the tweeter being a horn in the centre behind the gauze dust cap. They have an addictive sound.
The tonearm shouldn't be too tricky to rewire. Start a thread in the Past Masters area and ask for guidance, there are plenty of members with experience of these. Be very careful with the cartridge, they are easy to damage.
Enjoy the forum,
Geoff.
It is impossible for anything digital to sound analogue, because it isn't analogue!