Restoring hardware on your car will pay off in the long run.   Not only will you be keeping your car original, you won't have to search for the correct hardware in a catalog.  In many instances the hardware used on your Corvette has special head markings and symbols.  Much of the after market and even some of the restoration hardware will not be identical to the hardware removed from the vehicle.   There are numerous publications which identify the hardware used in the original assembly of your Corvette.  It may be wise to purchase one of these restoration guides prior to tossing out the crusty nuts and bolts you remove.  Aside from helping to identify hardware, these restoration guides take you through the entire process of reconditioning, stenciling, number identification and more.

To recondition your hardware:

Begin by making sure you know EXACTLY where the hardware came from.  Never loose track of the groups of nuts and bolts.  There are very similar nuts, bolts screws and clips that can be easily mixed up over a few years time.   Some have similar head markings but different lengths.  Body bolts in one area may have markings different than those in another.  Bag and tag everything!   Make a chart for future reference which explains the number and head style of the body bolts you remove and the areas they came from.  These bolts in particular, were used extensively in building the Corvette.  They have the familiar "E" stamped in the recessed head.  Another style bolt used extensively on the heavier frame, front end and chrome attachment points is the "A" style head.  There are bolts with other symbols too.  Sometimes you'll discover body bolts with an Anchor symbol stamped in the recessed head.  All of these have a particular location and should be put back where they came from.  Keeping track of these parts is essential for a factory reassembly.  Just as important is the time savings you'll enjoy by not having to spend hours trying to remember.

Cleaning:

Unless severely rusted, most original hardware can be made to look new.  The following process works especially well for larger nuts and bolts.  

1.) Begin by separating your hardware into groups.  Label a series of coffee cans for each group.  Put the crusty, painted and partially rusted hardware in the cans.  Dump enough paint stripper in the cans to cover the hardware.   Stir the hardware, allowing the stripper to fully contact all surfaces.  After a few minutes, stir again.  Now, using a rag or similar arrangement, dump the hardware onto the rag...stripper and all.  (You shouldn't have added more stripper than necessary to cover the hardware).  Wrap the hardware/stripper up in the towel/rag.  Now, using gloves, message the rag with both hands.  Keeping the hardware surrounded by the rag, keep doing this, rubbing the hardware together as you do.   This first process serves to loosen the paint, grime and surface rust from the hardware.  In addition to this the rag will help separate the excess stripper and heavier grime.  Now, clean out the can and dump some parts cleaner in it. (Its up to you to decide what should be used to clean the remaining crap off.) Go ahead and clean the remaining crud off the hardware.

By doing the above, you'll eliminate a large majority of the next step......

2.) Set up a medium grade wire wheel.  This can be done on a grinder or in a drill.  How you secure the drill is up to you but you'll need both hands.  Now, wire wheel the hardware with the heavier rust.  Using a pair of Vice Grips may help to hold onto the parts. Anyway, wire wheel the remaining hardware.   Put it back in the can of cleaner.  In the end, you want to have reasonably clean nuts and bolts.  You'll still have spots and imperfections on them.

3.)  Here's the trick...If you can find 1 Pt. plastic jars with screw on caps, use them. If not, use your cans.  You will have to have lids for them.....Dump enough Marvel Mystery Oil in the jars to completely cover the hardware.   Shake it around for about a minute or so.  Now, leave it in the can.   When you finish with the rest of the cans, set all of them aside.  Let the cans sit for several days or even several weeks depending on your next project of the restoration. As the Marvel mystery oil penetrates the surface, it will leave a corrosion barrier and a black oxided finish(Dark Grey) on the bolts.  The body bolts in particular look almost brand new.

Obviously there will be hardware which just isn't worth trying to rejuvenate.  Partially chromed screws, cadmium plated bolts and other hardware will have to either be replaced or re-conditioned according to that particular process.

Many of the after market body bolts have a thread pattern which is cut for an interference or self-locking fit. While you may be able to easily screw in the older ones after they've been cleaned, the new ones will seem very tight.   Although this may be a desirable feature, it may be unnecessary in many cases.   The likelihood of cross threading one of the new bolts is much higher in areas difficult to access.  In particular, fumbling around with the hood bolts because they don't thread into the holes becomes troublesome.  If you do get new body bolts, trial fit or break them in prior to actually installing them.

While your at it, take a tap and clean out the threads of the various bolt locations on the car.  In areas where bolt slippage may be critical, it may not be wise to apply an anti-seize or similar anti corrosion compound.  Its up to the individual to decide whether he wants to protect the bare threads.  In all instances, a thin coat of sealant can be used to seal the head of the fastener.  One of the best anti corrosion products is called Amalguard. Its characteristics may be duplicated by other products as well.  This corrosion preventative leaves a non sticky, clear anti-corrosive barrier wherever it's applied.  For restorations this is excellent because it allows the original colors and head markings of the bolts to be seen.   It is non-oily and can be cleaned or wiped over without causing a mess on adjacent parts.