Proof of card existence?

[pbspelly]

Hello. It's great to find this forum, and so many people who know so much about old cards.

I collect cards and memorabilia of my grandfather and great grandfather, the Billy Sullivans (jr and sr respectively). I have a pretty large collection now, most of which was acquired on ebay or from card shows or dealers. I can post a link to photos of my collection on Webshots, if anyone's interested. Some of them, like an old Plow Boy and a George Hull postcard, are pretty special.

Some of the cards I'm still searching for, though, are cards for which I've never even seen one with my great grandfather or grandfather on one. So I'm starting to wonder if they really exist, or if, perhaps, it was actually a different Sullivan or if his listing was a mistake.

For example, supposedly, there is a Pinkerton cabinet (T5) with Billy Sullivan Sr. I've had an ebay search running for Pinkerton cabinets for nearly ten years, and while I've seen plenty of other Pinkertons (often for astronomical prices), I've never seen one with my great grandfather. Likewise, supposedly there is also a Sporting Life cabinet (W600) of William Sullivan. But again, I've never seen one, which makes me wonder if maybe it was Dennis Sullivan or something (I've seen other card lists mistakenly list Dennis as Billy).

Similarly, I've never come across a Foto Fun or George Burke Postage Stamp of my grandfather Billy Sullivan Jr., despite his inclusion in card checklists, and despite seeing plenty of other of these over the years.

So what I'm wondering is, has anyone ever seen a Pinkerton cabinet, Sporting Life cabinet, Foto Fun, or George Burke Postage Stamp, of a Billy Sullivan?

Also, if anyone has seen a Rose Postcard Billy Sullivan for sale, let me know. I've seen a picture of one of these cards (so I know they exist), but never seen one for sale.

Thanks