Order and customer data only transfer

I have just spent the last 3 days trying to upgrade from 1.3.5 to 1.3.6 and have come to the conclusion I must have some sort of database corruption due to the many and varied errors I am getting.

Rather than continue to fight this and because the chance is a good one I have decided to do a fresh install of 1.3.6 (which I can do with no problems) and do a full redesign (I have got to replace 100% of the stock anyway).

Question :- Given that all the data I actually need to bring across is my customer and previous order data is there a quick and dirty way I can do this by just taking single table data from the old database to the new one and if so what tables will I need to copy the data from. Also are any of these tables affected by the .5 to .6 upgrade and what would I need to hack to make them compatable?.

Thanks in advance.

ADJB