Very difficult if not impossible to find a GnR machine that doesn't have some sort of wear in that yellow section around the inserts. If you did find one, it would be a pretty expensive machine I'd imagine.
I can't comment on the clear coat, the info already provided would be very accurate knowing those two guys.
Something I can comment on though is the quality of gameplay and over calibre of a GnR machine. For me it is the best DE machine I have ever played. Plenty to do, heaps of modes to work through, multiball is awesome but you must have all three magnets working 100% to get the full effect. Cool ramp shots, drop targets, captive ball, nice flowing loop shots and then there is the soundtrack. If you don't like the music it is still a good soundtrack for a pinball machine but if you like GnR's music then this machine takes it up to the next level of coolness. I would recommend upgrading the speakers though, huge difference. Even just putting a sub in the cabinet would make a big difference.
There is a reason that GnR is the only DE machine still to command big bucks when one comes up for sale. It is a great all round pinball machine and a machine that I would thoroughly recommend to anyone thinking about buying one.
What is the one worth on eBay......as much as you are willing to pay for it. I wouldn't like to see it go over $4.5 - 5k but who knows, it may go for less!
Oh, as you can see by my avatar, I had had a few in my time.