Hi James,
I just released an LTE cell scanner based on the rtlsdr library. If you're interested, the code is available on github: https://github.com/Evrytania/LTE-Cell-Scanner
This is exciting stuff, thank you for sharing! I had to change few lines (patch attached) for it to compile on my system, not sure it is the proper way, though.
This code will search for all the LTE cells in your area and will also report the frequency error of your dongle.
Works for me, found one carrier so far.
Best regards,
Dimitri