Fix it with the best condition/price OEM parts (DT,TZR,TDR) you can find without keeping originality, keep detailed notes of everything. Release the b@st@rd bike it can be and you like.
Have a collection of every Yamaha workshop/parts manual of every bike you took parts and even from the bikes you copied something.Build a labyrinth of knowledge for the DT and a lot others,chaos theory is your guide. It's Yamaha OEM after all but from 3 bikes!!! (Did it to mine).
Keep it original OEM with model specific parts and have the Yamaha workshop/parts manual as your guide. Stay safe and maybe hard find parts and expensive.