Good objective report, thanks. If you are feeling curious have a look around for pics of early Roketa db04, Kinlon R/T and SM.
www.kinlon.com.au
That frame is the same as are some of the bits. Kinlon uses the Loncin 200 cc engine, yours I do not know enough to say but maybe someone will chip in.
Let me know if you come across a rack that fits, I want one or two for me and mates!