Do you just want a pair of door mirrors, or a pair of chrome 1200 door mirrors?

There seem to have been two different mirrors used on the B310 Sunny range & one looks just exactly like the 1200 mirror, but chromed & I believe that they are still available new, although my left side one was a back order deal from Japan.

See if you can find one at a wreckers & confirm that the mounting screws are in exactly the same spots. Sometimes Datsun mirrors look the same, but differ slightly.