I don't believe there is any reason not to use the original pins of they don't get boogered up.
I agree. However, if the pins are loose fitting going back in, get new ones.
Also, as stated, use the proper size roll pin punch not just anything that will fit in the hole. This will prevent boogering up the pins. A bench block (steel block with various sized holes drilled thru) will be very helpful in driving out the pins.