If anyone is wondering about the lack of progress it is because I've discovered one or more errors in the drawings I'm using. I wish I'd calculated the resultant port timing from the individual component dimensions before I'd started - I'll know next time.
Very annoying to say the least
I've been more or less the same place, when I tried to restore my old Viking 2.5cc diesel. My attempt at a new crank interfered with the bottom of the piston at BDC, so I calculated the port timing and "discovered" that the exhaust and transfer times where a lot more aggressive than the inlet time, so I just decided to remove a bit of the bottom of the piston - Wrong Move
But I will say that wrong drawings are worse than just taking the wrong decision - I know what I did wrong, but you will have to figure out what is wrong with drawings made by someone else