On Numista it shows the Singapore 10 dollars p-11 as either a 1979 (p-11a) or a 1980 (p-11b). If you look on Ebay, most of the ones that are for sale are 1976 p-11b. I have seen photos of PMG graded notes with the date of 1976 p-11b, PMG notes with replacement star 1979 p-11a, & PCGS notes with 1980 p-11b. What is going on here? I even looked at a banknotes catalog and it only shows a 1979 p-11a & 1980 p-11b notes. Can someone explain? Thank you.