The older pocket doors ran on tracts on the floor & had roller/wheels mortised into the bottom of the doors; later ones are suspended by pulleys attached to the top inside of the door framing. In my area (central Atlantic) the older, larger door sets with the bottom rollers intact bring high dollar because they're scarce whereas the smaller doors on pulleys are plentiful & cheaper unless there is something special about them. The problem is finding someone who needs matching doors the exact size as the ones you have for sale.

Let's put this in perspective. Armed with a good electric screwdriver, I can change 70+ hinges in under two hours without help, by leaving the door in place and changing those hinges one at a time. Even with a normal screw driver, I suspect you could do it in less than 4 hours, but I always go for the lazy easy way myself. I'm not trying to set speed records, that's just about how long it takes. It bothered me enough at my sister's house, the I bought hinges, and replaced them everywhere but the front door in the time it took her to go to the gym and the grocery store. The front door (probably close to 80lbs) had a different shaped hinge so I had to use a trim router to fix that purchasing mistake or I would have been done before she returned.

Here's a website which may help.answer any questions: http://www.hardwaresource.com/hinges/cabinet-hinges/entertainment-center-cabinet-hinges

Yep, it's the paint. One of my pocket doors is totally gunked up and barely operable. Took me a while just to get the latch out so I could actually get it out of its pocket (pop-out latch was painted over so it wouldn't pop out when I pressed the button). Gonna need so much paint stripper... As for the fireplace, that's going to be stunning back as stained wood. I've never understood painting detailed woodwork white because it blanks it out and takes away all the drama. The tile might actually be white - one of my fireplaces has white tile (and the wood mantelpiece has been painted white... ugh), and said white tile is definirely original. It's pretty easy to tell if it's been painted by touching it. Also, I can see the cracks between tiles, and those get filled in with paint when you paint tilework. P.S. those decorative tiles in the corners look VERY familiar - I think I have the same design (but different color) on my dining room fireplace.