FWIW, I managed to get my hands on a translated copy of the honda manual for NSR250R and NSR250R-j-sp(1988 MC18?). Its in pdf format, appears to be the real thing but the pictures are poor quality. Its a big file so....if you're interested need to figure out how to get it to you.
cheers!
btw...the file is 15Mb. It may not be possible to email to some boxes unless your settings allow you to receive a file this size.