I suspect that the one you (re)posted, which I know to be really nothing more than a academic drill for industry on composite construction, might draw heavily from the earlier attack tilt rotor. There are several differences that I think make them different design efforts. One has fixed engines that Bell stopped work on a while back while the others have the (now) trademark tilting nacelles. One is a single seat while the other is two, something that is not a simple as carving out some of the fuel tank in rotorcraft. So while I suspect their is a lineage between the two concepts, I think that they are different works. Perhaps someone else on the Forum could provide more info....