Well, I tried laying the bike down on it's side and all that did was get a little bit of gas (not much) to leak out of onto the side of the tank. LOL. Oops.
So, I pried the chrome covers off and turns out that little nut had made it's way over to the other side of the handlebars (not "up" the other side, but it was certainly far to the left -- which would explain why it didn't come out tipping the bike over). This is likely because I've been riding the bike like this for probably 1,000 miles or so with the bar end off.
Anyway, retrieved the nut and got the bar end on and now I'm good to go! I rode it around to make sure I didn't overtighten and cause any issues with the throttle. And it's all good. Thanks for all the comments and help. Have had some interest in the bike (and possibly somebody to come and see it this weekend), so it's good to have that on and over with.
