You might try
http://gemm.com .
There are two things to consider. The value of the Lp as such and the value of the signature. I've been collecting Lp's for a long time and while I don't collect based upon value, nor do i know the value of most of them, I have not heard of Billy Vaughn material as having much if any value. So even the signature might not mean much. You might try placing it on eBay as an autogragh for Big Band item collectors. eBay can be a bitch in itself though .
I've got a lot of classical albums that I might be interested in selling if I could find a relative value for them myself. I have yet to find a decent place to do that, book or website. I do have some books for valuing rock and other more contemporary music records.
Oh, also if you are really trying to sell it as an Lp or if that is an interest of the buyer, then condition is everything. That can be a rather subjective hurdle too.
-Bill
