Scott, just another opinion...I would say the natural, linseed kind of finish caters more to the vise aficionados. The really hot paint job caters more to the overall general tool freaks. I think on something like eBay, the nice paint jobs will usually bring more. The tool aficionados are basically most of the people that follow this thread. They may know and appreciate the beauty of an old vise, but at the same will not pay big money (unless it is their holy grail), tool freaks there are more of and will pay to have any hot looking tools. (Balane does great paint jobs and fetches good money)
On your website, hard to say, what is your client base? (probably more "Vise Aficionados"?) If I were in your position, with the many vise to sell, I would paint them and not all at once, put them on eBay.
My 2 cents