I'm trying to grab a copy of the GNU Radio code through git which still has the old USRP inband code. I noticed this commit from Jonathan in my search:
Merged r11377:11390 from jcorgan/usrp-headers in to trunk.
* Removed usrp-inband code from tree (put into limbo directory.) This code has become unmaintained and has started to suffer
from bitrot. A checkpoint tag has been made for anyone still needing to use it: