right side of the car = passenger side. although jay-dee-eem datsuns had the mirrors on the fenders.

Good news, I'm going up there sunday to get it
hope all goes well

oh and which mirror should I move?

its up to you. IMO i like the look of the mirrors on the fenders, but everybody has there own tastes.

well which position will be the best as far as functionality?

you cant just more the mirrors to the fender you need to buy the fender mirrors which are like 300 dollars or some crap. just put them in the proper place for now and when you got the time and money to move them and fill the holes from the old ones and paint then do it

so the proper place is on the doors? cool

Note: if it really is/was a Black Pearl, it had mirrors on both sides (driver and passenger).
cheers,
Dave