1975 or 1974 Dt125



Hello I Have a Dt125 , not sure if it's a A or B . Also not sure if it's a 1974 or 1975 ? ( serial number refer to the 1974 as Brandy red color and the 1975 as being Chappy red colour.) Serial # 444- 108247 frame and engine the same .
The issue I'm having is the battery appears to be dead , the bike information I've read says it's a 6 volt system . The bike came with a Yuasa 12n7 - 3b battery, which I believe is a 12 volt battery?
The bike was running a couple years ago with this 12n7 -...

1975 or 1974 Dt125