Lovely job, be proud.
One thing though. You appear to have a breather pipe with air filter that emerges by your cambox, above the height of the engine. I don't think that's a great idea. All the condensate, oil mist and emulsion will be unable to escape, and twinks are hard-breathing engines. It is better to lead that either into a catch-can, or into the airbox as originally designed. Your way, all the gunk will end up in the oilpan, where you don't want it.
Ignore the above if I'm not seeing you arrangement clearly.