Given that the newly formed Linn products acknowledged in their first advertisement that they were now producing what was formerly known as the Ariston RD 11 as the Linn Sondek LP 12; I thought that I'd post two photos of a very rare Ariston which has the two button power switch set-up that was on the first Linn Sondeks. It is highly probable that this is one of the Aristons that was machined by Castle.
The text of Linn's first advertisement(Hi-Fi News and Record Review May 1973):
"Please note that Castle Precision Engineering(Glasgow) Ltd., 241 Drakemire Drive, Castlemilk, Glasgow, G45 9SZ, wish it to be known that they have designed(Design Copyright), Developed(Patent Pending) The special bearing and bearing housing assembly, and pressed steel chassis incorporated into the transcription deck sold up to December 1972 under the name Ariston RD 11. In order to satisfy consumer demands, we have purchased new premises adjacent to the present factory and formed the company of Linn Products Ltd and are now manufacturing our own unique product, the "Linn-Sondek LP 12" transcription deck."
You can find a reproduction of the ad in an article about the LP 12 in Hi Fi News magazine Yearbook 2009 (page 133).