OK, so I'm putting the bike back together after doing a bunch of things and I have 4 extra bolts in my toolbox that I can't figure out where they go.  They are black, have a 10mm head, the entire shaft is threaded about 12mm.  The head of the bolts are marked with a "7".  They're marked up enough to appear to have been removed and replaced before.

It is possible that they were already in my toolbox, but I don't think so.

Here's the list of what I did:

• Front fender / brake calipers removed to remove front wheel
• Front wheel removed / tire replaced / wheel bearings replaced
• gas tank removed to permit fork tube removal
• Front fork tubes removed / fluid flushed / springs cut 4" and replaced with PVC
• Mufflers removed to remove rear wheel
• Rear wheel removed / tire replaced / final drive removed / splines lubed
• Rear rack and plastic / bag antlers removed to fix brake/parking light wiring

One extra bolt wouldn't worry me too much.  4 identical bolts might hold something important on.

I suggest that you go over all the areas that you listed that you worked on, and if no bolts are missing from those areas that those bolts were probably already in your tool box. 

I suggest that you go over all the areas that you listed that you worked on, and if no bolts are missing from those areas that those bolts were probably already in your tool box. 

That's my current suspicion.  I took the bike out for a spin after double checking everything I could think of and nothing fell off.

Sounds like the bolts holding the front fender on, did you add a fork brace and remove the factory brace plate??

That's nuthin'.  After reinstalling the head on my 1976 FIAT 124 Spyder when having the valves ground, I had two bolts about 5/16 diameter and 8 inches long left over.  I took everything apart again and could find no holes to put them in.  Put it all backtogether again and drove it another 30,000 miles without any (other than the usual) engine problems. 

The OP's bolts sound like main fairing attach bolts.  ??

Sounds like the bolts holding the front fender on, did you add a fork brace and remove the factory brace plate??

Nope, those have 12mm heads.  Front fender is securely mounted, too.  No fork brace.

The OP's bolts sound like main fairing attach bolts.  ??

Haven't had any of the fairing off lately.  Did take the belly pan off to put the bike on the jack, but that doesn't use those bolts.

OOH!  I think I might have it!!!  Leftovers from removing smog stuff and adding block-off plates.  (Done a couple of months ago)

Yup, that would fit the description of the hardware that you found.

I've got to make sure to take all the extra hardware out of my toolbox before starting projects in the future.

I've got to make sure to take all the extra hardware out of my toolbox before starting projects in the future.

Years ago I was doing a top end rebuilt on my 71 Shovelhead, and after installing the pistons, barrels and heads I found one of the circlips for the wrists pins as I was cleaning up around the bike. So I had a 50/50 chance to pick the correct cylinder to remove, and as luck would have it, I removed the wrong cylinder so I ended up removing both of them again. 

Back when I was a Navy electrician, I always kept a couple of extra bolts in my pocket. When I would find a new guy doing some maintenance, I'd slip them into his pile if bolts then come back when he was finished and standing there scratching his head. Good times. LOL.

Back when I was a Navy electrician, I always kept a couple of extra bolts in my pocket. When I would find a new guy doing some maintenance, I'd slip them into his pile if bolts then come back when he was finished and standing there scratching his head. Good times. LOL.

One of the airplane shops I used to work in, the engine shop manager used to do that.  One day I took a used oil filter screen, packed it full of aluminum and steel shavings from the machine shop, and mixed it with a set of engine parts he was tearing down for analysis/overhaul.  After he recovered from his near heart attack I told him what and why.  He never did that again.