I bought a 10 speed favorit special yesterday for 20 euro at a bike auction just because i liked the look of it and it didn't seem too banged up. it's lovely really, all the original brakes and everything. fixing it up now but i'm just confused about when it was made. how would i tell from its serial number? another problem is that the serial number is almost worn off. i think the first two digits are 86. is that the year it was made?