My piano buying strategy has lately turned to the idea of buying a good quality small grand that needs restoration. This has several advantages for me chief among them being that the time required for the restore might allow 1. a series of spread out payments as opposed to floating a big loan and 2. give me time to finish a studio in which to put said instrument. I'm very comfortable selecting an instrument based on playability and timbre when it's right there in front of me but how do you select one when you won't know how it will sound/play until it's DONE ? Also, what sorts of rebuilding options are available? I've heard of Yamahas being rebuilt with Steinway parts and Baldwins fitted with Bosendorfer hammers - is any of this true or just sales hype? (Just to narrow the inevitable onslaught of options down a bit - the candidate I'm currently considering is a Baldwin M)

Find the restorer first. Most pianos take on the character of the last person who worked on it, so if you find a restorer whose work you like, you should be fine.

And that restorer may have restored or rebuilt pianos (those are different procedures) for you to try. At the store where I worked right after school, the customer could try the piano (already owned by the shop) before work was started and after work was done, with no obligation to purchase unless satisfied. I don't know how common this system is but I saw it work well for both shop and customer.