2 days and it's only 120* I/T? Since this isn't cured, you probably have the makings for a trip to the hospital if you eat it.
The Little Chief Smoker isn't designed to hot smoke. It's for smoking fish, smoking/drying jerky...things of that sort is about all it's good for...lower temp smoking and drying.
You may want to slip by the food safety forums and read up on what you've got going
HERE, or check the link below.
In a nutshell, what you have is a meat that has not been cured, soaking in a low-temp smoke chamber for way too long. Even though it was brined, this is a serious potential for illness. Generally recognized safe methods for smoking a cut of meat such as you have will include approx 225* smoke chamber temp, and at that temp, your lamb shoulder should have reached an internal temp of 120* in about 3-4 hours, and should have passed the minimum safe finished temp of 145* shortly afterwards. Hovering in 40-140* range (danger-zone) for this long without curing the meat is a huge risk.
Here's the goods:
http://www.fsis.usda.gov/Fact_Sheets/index.asp
http://www.fsis.usda.gov/Fact_Sheets/Safe_Minimum_Internal_Temperature_Chart/index.asp
Don't mean to rain on your smoke here, but it's pretty clear-cut what should be done.
Also, if you don't mind, drop by the
ROLL CALL forum and introduce yourself so we can properly welcome you to the SMF family.
Eric