There are a couple of russian (?) sites that have digitized plans that can be downloaded, printed and scaled (via xreox machine). They were active as of 3 months ago. try them
http://wherewolf.narod.ru/
http://www.airwar.ru/other/drawe.html
http://www.aviacherteg.narod.ru/index.html
By last count, this last site was slow, the drawings are good so be patient. It also only allows one dnload - so just logoff and relog on.
3d modelling is an option
a true mental excercise in frusrtation