I'm interested in locating replacement nibs for the Toshiba Digitizer Pen (EMR) for the WT310 Pen: PA5133U-1EUC I noticed that nibs from my Lenovo (X61 Tablet) Digitizer Pen and Toshiba (M200) Digitizer Pen do not fit this pen, as they are too thin. I do believe they are the white felt tip type nibs. Any advice would be appreciated P.S. don't own a pair of calipers