Usually the displays are specified at something like 10 mA per segment. So 100-160 mA is a rather high current. Also the 74ls47 does not provide that much current. How is the current changed ? - usually it's a resistor per segment - so not much to change, as the 74ls47 like a rather constant supply.
Tolerance of the resistors does not really matter, as the LEDs have tolerances as well.