Bart THANK YOU for (very) valuable points . I have done massive amount of code conversion work with my own hand . Everything fine, except i don't want to use GPL in final Prj-D . So I have searched & found MIT based alternative project Prj-M to replace the earlier Prj-G (GPLv2) , performs (almost) same function , i will use this Prj-M as base to re-create/re-write Prj-D again & give it a new name Prj-D2 . So i have added an "EDIT" section in my Question with these new info/data , Would you Please also add an "EDIT" section, to answer the questions inside EDIT section ? Thanks in advance.