My first thought was, why would an racer like an RA have a stand! But then looking at the catalog reprints, there it is, and a center stand no less! The works were racing the RA (with historic results) in 1923, but I am not sure when they were first offered to the public. They do turn up in the catalog for 1924 and 1925, both catalog illustrations showing the stand. 1925 was the last year for the RA, and it was superseded by the substantially re-designed I.o.M./TT models using the (then) new 82mm stoke engine. 1926 and later frames do not have provision for the RA stand.
-Doug