The fate of this airframe is unknown as it is never mentioned in the log books after 1929.  There are juicy rumors that it may have been used during prohibition for flights best not logged.  A recent call (5/23/06) to the FAA registry confirms that NX12084 was issued an experimental registration in 1931 as S/N 60 with a Henderson engine.  This would have been a converted Heath-Henderson 25 hp motorcycle engine.  Although NX12084 had good flying characteristics, it was definitely under powered.  When Continental introduced the 37 hp A-40-3, Jack Rose installed it on NX12084.

Barry Taylor has speculated that the airframe may have been reworked by Jack Rose and became the production prototype NX13677, but according to Peter M. Bowers in his article "The Rose Parrakeet", June 1974 The AOPA Pilot, vol. 17, no. 6, pgs.30-33, "The number [NX12084] went out of circulation when the dismantled airplane was stolen from its storage area . . ."  Unfortunately, Bowers doesn't say when the theft occurred.  Assuming paper documents can be retrieved from the federal registry,  we may have more information soon.

Although the general size and configuration of NX12084 is similar to the production Rose Parrakeet, as Barry Taylor pointed out, there are some obvious differences.  First, the cabane struts are of the "A" frame type on NX12084.  Second, the lower wing on NX12084 is "underslung" rather than faired into the fuselage.  Third, there is no diagonal interplane strut.  Fourth, there are only a fore and aft vertical strut between the wings without the characteristic "N" strut. Fifth, cowling shape.  Sixth, NX12084 has a step built into the side of the fuselage.

By the late 60's the registration number was still unassigned.  In 1969, Doug Rhinehart registered his first production Rhinehart Rose Parrakeet S/N 505 as NC12084 and called it "Sentimental Rose".