I searched dt250 and read the articles about carb and float. The pictures I found showed the float arms straight. I also found someone said 75 was different from 74. Before I bend these float arms straight, am I correct in thinking these arms have been inaccurately bent over the 48 years by someone trying to adjust the float level and not adjusting the tab. Also is the correct float level on a 75 the same as I found on here for the 74     17.3 , or basicly level. 
Thank you for your help getting this correct. 

edit: it doesn't look like my photo uploaded. Then I read the front page where photos are not working ? ....

The carbs are different on the 74 and 75 DT250. I have both bikes. 17.3 + 2.5mm is what is listed on page 8 in the service manual located in the tech library. Im sure if you have a look at that and scroll down further to where they get in depth about the carburetor you will find all the information you need.