The description of A105 which you indicated is OMB part number. Which do not differentiate between A105 and A105N for OMB internal component number as all A105 material are dual grade to OMB.
As for the Hardness, it is an average hardness only with material within around 1 year old does it have 2 hardness reading. As you can see the Heat Code 13/75689 this material is manufactured in Year 2013.