OK, here is some pictorial evidence which seems to support that. First, two pictures of the Linn, serial number 91, very recently sold on eBay. These come from the ebay listing:
(Unfortunately, I'm having trouble with hosting the pictures, due to the file format, so these are direct links to ebay's picture hosting. When ebay take them down, they probably won't display here any longer.)
Now, some pictures of an Ariston RD11, serial number 21, sold by Hamish Robertson in August 1972. These came from the recent thread on Ariston history on another forum: (see here:
https://audiokarma.org/forums/index.php?threads/ariston-history.1054333/)
20240315_135945 by
grilled snapper, on Flickr
20240315_135956 by
grilled snapper, on Flickr
20240315_135951 by
grilled snapper, on Flickr
As is easily seen, the two decks really do look identical, apart from the removal of the Ariston branding on the armboard. (Also, the motor pulleys are different, but there's reason to think that the one on the Ariston has been replaced at some point.) The most significant evidence however is that the two decks clearly bear the same two labels. On the Ariston, the silver inspection label has been signed W.J.R. Those were Hamish Robertson's initials. On the Linn, the identical label has simply had "Manufactured by Linn Products Ltd" typed onto it, as well as a serial number. The yellow label on the Ariston bears the heading "Ariston Audio RD11". On the Linn, the exact same label is still there, but with the top and bottom cut off, removing the Ariston branding. A bit cheeky! (Note that these yellow labels, which pre-date Linn, mention the single point bearing.)
Creating the first LP12s was pretty simple, it would seem.
