I had my eye on a 66 A with a complete factory A/C non working in very good original shape but I actually prefer a 64 or 65 & if everything will likely have to be replaced with aftermarket stuff maybe I should pass on it & look for a suitable 65/66 & add the whole aftermarket kit. does this make sense or should I stay with the all original 66 & replace with aftermarket stuff the items that need replaceing. this is my first time refurbishing an A/C so I am clueless here. EDIT is going with r134 a good plan?