DT 125 LC mk1 2 or3 ?

Hi there every one need a little help or ideas

I brought this dt 125 lc engine of EBAY and I am having a little trouble verifying which model it may be. I will start of by saying it is not a power valve model and I am using the blue Haynes manual as source of my data. The carb seems to be from a mk3 as its 26 mm and the serial number matches( although it this may not be the original). The alternator wires match up with the mk 3 diagram aswell as having an external pick up( could this have been changed to convert tp 12 volt). No mk1,s had power valve right,but what about mk2 & mk3,s are they all power valve or was it fitted to just certain models.Engine number 12W-003146

HEAD AND BARREL 10V00

THANKS FOR YOUR HELP ALL