I would personally try to save as many of them as you can.
Trust me on this,
@Huw recently tried it out too and the results are great.
Put all your nuts and bolts through a petrol or thinners wash to get the paint and grease off - the grease would prevent the next stage working well.
Get loads of cheap and nasty lemon juice 6-7 bottles @60p/ea from the supermarket, pour into a bowl or container. Add a table spoon of sea salt and stir. Then pour all the said rusty metal parts into the bowl and leave for 12-20 hours. You will be stunned at how good they come out and how much rust disappears. Beware though, the solution after the soak smells sulphurous and may not be a ideal to inhale it in an unventilated area.
Once you pull them out, they will need neutralising quickly - rinse well with water and then use the liquid Jenolite or other solution to take care of them and prevent future rusting while they await plating.
I used a company in Crawley called YB Plating - while not the cheapest, they were great, not silly expensive and offered to keep my items separated and bag them as I had (I bagged and tagged all nuts / bolts etc).
If you do plate them, make sure you clearcoat things like fuel rails, pulleys, brackets etc as the plating will still go off after some years and lots of moisture.
So why go through this hassle if sending them off to a plating company anyway? Well, I found that while they dip them in some kind of acid, certain parts didn’t clean up well enough for the plating to look as good as it could have.
Here is a before and after using the lemon juice / salt solution and an old ice creme tub (I think this was an overnight soak of about 12 hours) ...
