Gattonero wrote: .... but even when I was working as a Courier my thoughts were "spending 2-3hrs trying to fix somethign that would still be old, or make 3hrs overtime to make more money and get a new one?"
Besides, the old parts work as spare when in need and no other alternative is on sight.
As I mentioned previously several times, after they have been serviced properly they are 'better than new' in that
-if they are new and unworn they have zero free play in after they have been serviced correctly and
- if they are used then they are (unlike nearly all new ones) still play-free even if the freewheel bearings are not perfectly smooth any more.
- if there is any free play the wear rate is vastly higher than if there is no free play in the bearings.
It may offend your sensibilities if the freewheel bearings are slightly rough-feeling but that is all it will do; it has zero impact on the actual running of the machine. By contrast the idea of putting a knackered freehub body back on a wheel without doing anything to it first, having 'kept it as a spare' seems like utter madness to me.
fastpedaller wrote: .....Also (for me anyway) I relish the challenge of bringing it back from the dead! As regards new freehubs, do you have advice on 'making them better from the start' eg should I try to inject some gear oil in before I use.
My advice is to;
a) use them for a short while ( a few hundred miles tops)
b) re-shim them and
c) to use a semi-fluid grease inside them which contains good corrosion inhibitors.
Gear oil is OK but it does not have enough corrosion inhibitors and it will leak out unless the backside seal is both present and in perfect condition. A #2 grease is too thick and will gum up the pawls too easily.
The idea of using a freehub body for a short while is that the bearing surfaces will be 'run in' and won't wear more in service, provided they are adjusted to be play-free. Most freehub bodies don't have finish-ground bearing surfaces and in these the first few microns of wear will occur even if the new freehub is adjusted to be play-free.
Obviously with a few exceptions you don't know if the bearing surfaces inside the freehub body are ground or not so you might as well use the freehub for a short while before adjusting it, provided the weather doesn't get inside before decent/sufficient lubricant is added.
It is as well to note that you may as well overhaul a freehub body when it is basically new; if you don't it will (unless by some miracle it is genuinely play-free) wear and need re-shimming sooner or later anyway. As well as accelerating wear, any free play helps the seals to fail on the freehub body too.
If you do what is required when the parts are undamaged and keep them well-lubricated, the chances are that the freehub body will outlast the wheelset.
If you do nothing to it, the chances are excellent that it will be the first thing to fail.Even with rough-ish freehub bodies, the chances are excellent that when you service them, it will be the only time this will be required, i.e. the freehub body will
not be the thing that limits the life of the wheelset.
I think that I have only gone into the same freehub body for a second time on a handful of occasions, and nearly all those were anticipated beforehand. A few times I have had a rough freehub body that I want to have *perfect* again; I've run this body for a while, so that I can see exactly where the balls are running, then I've reground and polished the bearing surfaces where necessary so that they are almost blemish-free, and reassembled with new ball bearings and adjusted to zero play. Better than new....
cheers
) a 500ml tin of zinc-rich primer for my car chassis. This is seriously heavy paint at 1573g for 1/2 litre! Guy said he holds onto the can when he hands it to customers in case they drop it 
