Stay away from Ring Audio for vintage tube audio. They recycle alot of parts instead of installing new ones. If you need tubes, heck they don't even know how to properly bias and adjust polarization for radio tuning.
I suppose Ring can fix a turntable or straightforward solid state board which at best requires a bit of soldering ability, but beyond that I'd sooner leave the unit out of commission than to trust these dishonest hacks !
Ring, if you're reading this and wish to prove yourself to be capable. How about we put a camera in front of your best technician and see how well you can perform a vintage tube restoration.