The bottom gasket between cylinder and the case...why are there two gasket sizes?  I tried to buy one on ebay using the right part number and it's about 10mm too wide.  I learn there are two types and I am getting the other one on the way (thanks to the best parts guy I know Buzzard.)
more importantly, do you use like a blue permatex or yamabond on said gasket?  Thanks in advance this green machine could come together sunday or Monday with a little luck  

Short answer: Shared parts lists for similar models that got screwed up when they went digital.  You have to be careful and pay attention to part prefix (model code) and then it's still tricky sometimes.  Been discussed here at least 100 times so if you search you'll find a lot of info.

Partzilla lists are a bit of a cockup for DT2 & DT3. DT1 list gets it right--same base & head gaskets for yours.
www.partzilla.com/catalog/yamaha/motorcycle/1971/dt1e/crankcase

I have to get better at the search function! Thanks for the help