I used a KR1S barrell for inspiration, and will try to copy the port map as well.

I'd already smoothed the side transfer entries and knife-edged the dividers previously. I've only attacked the side transfer (upper left of pic) and the rear transfer port so far.

The close-up gives a bit better idea of howmuch meat has been removed.

The rear transfer no longer has that massive step at the gasket face.
Doing the port timming is really tricky since I dont have a right angle drive, but is still do-able..... just.
Still a long way to go though.