Cutthroat First was Hun-Grrr...now CUTTHROAT,can't have Hun-Grrr without the other TERRORCONS,here with his G1 counterpart.
A very unorthodox - and successful - use of the Universe Silverbolt mold, friend! Only thoughts I have would be to make the beast head sit a little more flush on the chest in robot mode, but regardless, that's a bang-up job!
Looks terrific! My only critique though, compared to his G1 counterpart, it looks like you place his wingtips upside-down. Excellent job none the less.