"Impaired glucose tolerance (IGT): A person is said to have impaired glucose tolerance when the fasting plasma glucose is less than 126 mg/dl and the two hour glucose level is between 140 and 199 mg/dl. This is sometimes referred to as "prediabetes" because people with IGT have a higher risk of developing diabetes."
http://www.medicinenet.com/script/main/mobileart.asp?articlekey=46359&page=5
Your fasting glucose of 89mg/dl (4,9 mmol) is in the non diabetic range.
Your glucose intolerance test result at two hours of 188mg/dl (10,4 mmol) is in the pre diabetic range indicating that you have some degree of insulin resistance.
With these results you are unlikely to be a diabetic, whether t1 or t2, and are probably pre diabetic but only your doctor can give you a proper diagnosis.
I too am not familiar with the C peptide test. All I know is that it is an indirect way of measuring insulin production by the pancreatic beta cells. Both your c-peptide and insulin results appear to be within the ranges you list, which I assume are the normal ranges.
Pavlos
