You will need to make an adjustment in the "FFT Display" section to the "Shift" parameter to match your offset. In my particular sittuation 140 Hz seems to me the magical number to allow the frequency to line up accurately in the waterfall.
Also you will need to uncheck the "Swap" in the same section as this was what was causing my frequency readout to be extremely innacurate.
See Photo Below
Other notes of interest:
1.) Depending upon your particular type of RTL-SDR Dongle, you will not have the option of using SDRSharp.R820T.dll in the drop down list. Instead I have found that if you use the RTL-SDR/USB for Q Sampling (HF Bands) and RTL-SDR/GUSB for the VHF/UHF and above bands with each set accordingly, you can just switch between the two different DLL's depending upon which spectrum you are targeting.
2.) The particular RTL-SDR Interface unit that I am using is a 100KHz-1.7GHz full band UV HF RTL-SDR USB Tuner Receiver/ R820T+8232 AM FM CW bought off ebay and, of course originating from Hong Kong, China. At the time it was $34.95 which included shipping and it took about 20 days for it to arrive (during the holiday season).