I kind of go along with what andrewjtx is saying - it is really difficult to
really know how good the condition is inside the hubs. From the outside it looks like whoever changed the bearings didn't use a puller - they were hammered out. I personally would not have reused a part after knackering it like that - but it doesn't necessarily mean that the bearings inside are shot.
You can however check the end float (play) by setting up a dial test indicator (DTI) / clock gauge... when installing these bearings you are meant to tighten the lock nut until you reach 0.04-0.06 mm
http://www.peachparts.com/Wikka/W123RearWheelBearings
My advice would be to measure the clearance before making your mind up about the condition of the bearings. You also need to consider other things such as smoothness of running / weird noises etc etc... be very critical of this as it will probably be 100% worse when you fit it to the car.
As for the condition of the trailing arms - what is that line on the trailing arm sitting on top?
If that is a crack or a bit of plate work welded on top - junk it.
As for overall condition - go for gold with an angle grinder and a wire brush attachment. Give it some stick. If you make holes - junk them. It is much better to make holes and find problems with them now.
After you've cleaned them up put on something like POR15 to protect (at least 2 coats) and then top coat with their chassis black for a really good job.