Don't obsess over the issue of new or reuse. This isn't a knock on your mechanical abilities - but your questions (wisely asked) illustrate a lack of experience - just go ahead and install new bearings, races and seals. The cost-relative to the important job the bearings do - is minimal.
Personally I have no qualms about using a steel drift to drive out the old races but a plastic, brass, wooden or leather mallet should be used to get the new races started in the hub and finish driving in with a brass drift. When doing the driving OUT part look for the small "cutouts" in the hub that allow access to the edge of races for your drift. When doing the driving IN part listen to the sound of the drift against the race -- when the race hits bottom the sound will be different.
Correctly packing the bearing is of utmost importance. Put a glob (a little smaller than a ping pong or golf ball) of fresh grease in the palm of your "off" hand. Grasp the bearing with however many fingers can fit into the center of the bearing and with the wider end facing down dip into the glob's edge forcing grease into the bearing. Do that until you see grease being squeezed out between the rollers and at the far end of the bearing. Rotate the entire bearing in your fingers to the next spot that needs grease and repeat the process until you've worked your way around the bearing. Put a layer of grease inside the center of the hub.
Be sure to remove the old rubber seal on the spindle and install the new seal with the "flared" end facing out. Smear a tiny amount of grease onto the inner bearing retainer where it rubs against the seal.
I think the '88 has a castle nut with a built in "washer" surface so after tightening the nut to fully seat the bearing follow directions as far as final adjustment. Older Volvo models (and most other older cars in general) have a separate thrust washer. After seating the bearing I back off the nut and then re-tighten it till there's no play but loose enough that the separate thrust washer can be easily slide side to side with a small screwdriver (as taught to me by the master German MB mechanic I was working under). -- Dave