I think the terms vintage and rare should be taken with a grain of salt on Ebay, I see people calling Japanese Fender Jaguars made only a few years ago "vintage", and getting the models wrong...
EBAY-MOMENT
"I gotz dis Vintage 2007 Fender Jazzmaster made in Japan and handcrafted in the usa by these elves. The Elves models were rare, you can tell by the elves sticker on the back of the neckplate. And look at all that mojo, I think Courtney Love played this guitar with Son House and Blind Melon Chitlin at the hoopajoob club in 1934. Starting big is $10,959.00 and shipping and handling will be $105.99 to all places in the lower 48 states."
(insert shameless company plug and mission statement here)
ENG OF EBAY MOMENT
As for the Mustang, I can see how this kind of stuff happened, I don't like it, but I know why. Back when Mustangs were cheap, the kids with them could not afford anything more expensive (or were too impaitient to save up for what they wanted), so they would take the Mustangs and so fourth their parents bought them, rip em' up, put alll the latest mods on them, and then use them for awhile before selling them off when they realized how stupid they are being....here's an example of a life of one of those gutars....
The lifecycle of a Vintage Mustang
- Some guy buys the guitar in 1966, lovingly plays it for about 5-10 years, and sells it off
- In the 70's, a punk rocker gets his hands on it, punks it out with stickers and a humbucker
- Ah, the 80's, guitar is sold to a pawn shop and sold to some high school kid for $50, he proceeds to replace the stickers and damaged olympic white with a rattlecan wannabe EVH paintjob and sticks on a Kahler trem.
- Late 80's....everybody wants something wacky shaped, so said kid cuts the body up in 4 or five places to make it look less "round", more like a Dean or a Jackson, guitar now barely resembles a Mustang, has 2 EMG pickups in it, and is painted black with skull and crossbones across the back.
- 1990's - Guitar is bought up by a guitar shop for $20 after kid can't make the light bill. Guitar store has another Mustang body sitting out back, so their wizard technician reuses the original neck and throws it onto another body with bits off the other Mustang.
- Still 1990's - Guitar is bought for $500 as an "original vintage Mustang", 12 year old Nirvana fanboy decides he wants a Seymour Duncan JB to be just like his idol, Kurt Cobain.
- 2000's - Guitar winds up in a prestigious shop, with a vintage guitar nut who likes Mustangs for the cult status they have (because it = $$$$$). He strips the finish, filles in the cavity for the humbucker (or not), repaints the guitar Reranch Sonic Blue, and sells it to $4300 to some sucker passing it off as a rare vintage instrument.
So yeah, you can see that I'm a tad jaded when it comes to the whole vintage collector/modified thing. I pretty much assume all vintage guitars have been tampered with to some degree, unless I'm given good reason to believe not.