Brother why don't you look for a tyre with 165-175 mm width, aspect ratio as 65-70 and tyre diameter as 13"?
For such a tyre, overall diameter will almost be similar to 155/80/R13, however, good thing would be, it would be readily, easily and cheaply available in the market, may be offered by many reputed brands, and it will also provide excellent road grip (with some compromise on fuel efficiency).
155/80/R13 is very hard to find here, I believe! As it's not a commonly used tyre size. 80 aspect ratio is quite large.