I am not honda wala bhai, but still read this link for new models in production:
Honda launches next generation CG125 and CG150 bikes in Brazil
Regarding OHC vs OHV read this from honda cg125 awardspace webiste:
"All around the world from 1976 to 2008 all Honda CG125 used a carburettor and a OHV engine.
Since 2009 all new motorcycles in most countries around the world stopped using OHV engines due to new emission laws.
In most countries they have replaced the Honda CG125 with the Honda CBF125, others use a modern Honda CB125.
But in Brazil they put a OHC engine in to the Honda CG125."
As the above statement clearly states that the main reason of switching to OHC was due to emission laws, where as in Pakistan euro-II was made compulsory from June 2012, so atlashonda came up with euro-II compliant engine. If the Govt make it compulsory for euro-III or higher emission standards, then they will definitely swtich to OHC or EFI system (the will be forced to do so).
For honda cd-70, search for honda cub, and you will find a lot of material to read.