Very cool, just pulled the trigger for mine 5644R, should arrive in my apartment for <$400. Thanks very much for posting the files, it will be a nice Christmas project for me.
However I noticed a problem in 20 minutes after paying, the semi-rigid link between CAL IN and CAL OUT was removed by some dumb guy.
Despite the seller claim it to be in “Excellent working conditions”. I'm going to replace it with the best SMA cable I can find, and hope the VST not that sensitive to this.
I also want to help hacking together the Gnuradio blocks, although not sure I'm competent enough in the hard core C/C++ part, but I can try.