Where can I find original parts for my vintage guitar?

Hello there folks, I’ve had a 1954 Gibson J-45 for a while that I salvaged from a raggedy alligator skin case in my grandparent’s basement. The guitar belonged to my great uncle who notoriously loved wine, women, and song, and after God knows how long in the basement the guitar has suffered some damage.

The celluloid tuning heads have long since shriveled, cracked, and disappeared, it is missing its strap button, the varnish is superficially cracked, and it doesn’t have strings or bridge pins for holding the strings in place. I really want to restore the guitar as best I can (I’m not going to mess with the finish) with original parts, but I don’t know where to begin.

So my question is this: Where can I get original tuning machines, a strap button, and bridge pins for the guitar? I’m not planning on selling this guitar, but I’m also interested in knowing the value if anyone can provide me with a ballpark estimate. I’ve seen them going for anywhere from $1999 to $12,999+