Just put both of the swingarm bearings into the swingarm.... however in my excitement of putting them in I forgot to put the grease shield back in.... Any comments on whether I should improvise a shield from the inside of the swingarm (its the side closest to the driveshaft) and only fit it back in place if I have to replace the bearing again...

or

do I take the new bearing out... or as I will be disturbing the whole thing is it a case of new bearing?

I would put it in now. Those bearings lead a very hard life down there and need all the help they can get. I have often toyed with the idea of making a better shield for them but as always there is something else that needs attention first.

definately put the shields back in ( mine are brass discs araldited in , as i destroyed the originals getting the old outer races out ). Then fill the area with as much waterproof grease as you can, as these bearings can be subject to a lot of corrosion. When i first got my bike, the pivot pins were seized into the bearings and had to be renewed also.