There are two YouTube videos of an actual, functioning Garrard RC-100. The first one is amazing enough, as it shows the changer handling records and turning them over; but the second is even more astounding, as it shows the mechanism underneath, that makes it all work:
1938 Garrard RC-100 Turn-Over Record Changer
1938 Garrard RC-100 Bench Test
The story about the entire production run of RC-100s (which were wholly dedicated to the USA market) going to the bottom of the Atlantic when the British merchant ship carrying them was sunk by a U-boat has been told many times. Apparently the few surviving RC-100s were prototypes that were sent to the USA ahead of the main shipment, or that remained at the factory in Swindon.
I serviced many Fisher consoles with Garrard record changers. For the most part, the electronics in those consoles were identical in circuitry to that in Fisher separate components. Changes were made for packaging the equipment in cabinets but those were extremely high-quality (and expensive) consoles. The Garrards did them credit.