Ideas how to convert rotary phone to gsm

Im trying to find the right path to change my old rotary phone to gsm, i already found a way to read the signal from the rotary wheel. Is it possible to reuse a old nokia gsm for an example for this kind of project ?

my code is like this

//lesari fyrir skífusíma - reader for rotary phone wheel

const int puls = 2; // - pulse from rotary wheel const int normalopen = 3; // - switch open when rotary wheel is in normal pos

int talning = 0; // - counter for pulses, outcome is the number that were chosen int vartalning = 0; // - counter that makes one count per LOW int telja = 0; // - on swich when rotary wheel is in use

void setup()

{ Serial.begin(9600); pinMode(puls, INPUT); pinMode(normalopen, INPUT); }

void loop() { if (digitalRead(normalopen) == HIGH && vartalning == 0) { telja = 1; } else { telja = 0; }

if (telja == 1 && digitalRead(puls) == LOW) { delay(20); vartalning = 1; }

if (vartalning == 1 && digitalRead(puls) == HIGH) { delay(20); talning++; vartalning = 0; }

if (digitalRead(normalopen) == LOW && talning > 0 ) { if (talning == 10) { talning = 0; } Serial.println(talning); talning = 0; }

}

Here is how the engineers at SparkFun did it, creating the "Port-O-Rotary" https://www.sparkfun.com/tutorials/51