Hi friends. Could you please tell me if this guitar is genuine?? It's supposed to be an Rg550 from 1987, but notice the H-S-S configuration. Someone said it looks like an rg560. He's asking for $400.

It sure does look like a 550 that someone changed the pickguard to HSS configuration. I am pretty sure that if you take the pickguard off you'll find that the body is routed for a humbucker in the neck position...
RG560's didn't have a pickguard...

In Japan they call it RG 540. it's genuine.
I think it's japan model only.

What jazzedout said. ^

Is the trem spring cavity cover supposed to have the 2 middle screws in a kinda diagonal spacing and not straight across? I thought that was one of the flags that it was a counterfit??

I'm with jazzedout too! The spring cover could be aftermarket.

Some things on it look off for me. It still may be a 550, but is is at least heavily modified, which in my opinion does not justify the asking price.
It looks generally in good shape but has clear signs of wear in several areas, I cannot verify wear on frets based on these pics. However you may need to consider in the costs for a makeover by a luthier.

RG550s with the singlecoil in the neck position are rare as hell in the US. Like psycoshredder said, they were called RG540s in Japan.

To tank - It's totally genuine, completely stock (aside from the strap buttons and possibly the spring cover), and rather collectible.

If you don't buy it, I'm gonna.

...which would explain the missing screws.

Yeah maybe the holes didnt match up so he didnt screw in the middle ones. I know my S series has offset middle screws in it's spring cover, but my RG is in the shop so I can't check off hand.

I wouldn't worry about the pickguard or the backplate. It is probably routed for the humbucker in there, and if it's NOT, then it makes it even more rare, right? So that's a bonus. The backplate is not original. If the neck is in good shape, with no headstock cracks, it's worth whatever you're willing to pay for it.

The body has a 550 stamp, so my best guess is that it is routed for a humbucker already...

Thanks for the replies guys! It looked a bit off to me, that's why I wanted to be sure it wasn't a fake. Just one more question. Notice the colour variation in the back of the neck, around the nut, it has a C shape. Is it something ordinary??

This is normal. The neck is two pieces and this is the joint between them.