Well, that would be very strange since they only ever made their first altello in 2010 and presented it for the first time to the Frankfurter messe . I think you might have had another brand but not a R&C.
There are many straight altos and few less straight tenors around.
Among the altos there was the Keilwerth as Rhys has, no longer in production, and the Wisemann (which is a Chinese horn closely resembling the Keilwerth)
Actually not true- we definately had one made up for a customer in the UAE about 2-3 years ago.... distinctive remember it as it was such a unique instrument.... it was the bottom horn on this page- http://www.sax.co.uk/acatalog/Alto.html
I know that Claudio sells prototypes to some good clients who go to see him and sax.co.uk is one of his best clients and has priority on " normal" people (as you had to experience yourself). So for example the first solid silver alto and soprano were sold to a distributor before they were shown for the first time in Frankfurt but I didn't think this would have happened with a project that ad stayed a " secret" for a while (as for the curved and semicurved sopranino or the future bass and contrabass) which was the case with the altello.