Serial.write() indeed writes byte values.
You can use those byte values directly to reassemble the int (a regular int is 2 bytes, a long int is 4 bytes):
int i = MSB * 256 + LSB
Serial.write() indeed writes byte values.
You can use those byte values directly to reassemble the int (a regular int is 2 bytes, a long int is 4 bytes):
int i = MSB * 256 + LSB