The good news is you should be able to get replacement ribber grips from Taurus or Hogue monogrips from getgrip.com (model 73000 I believe and highly recommend). The bad news is all other titanium parts probably can't be found (short of buying another M627T). Small/standard Tracker parts can probably be purchased from Taurus, although some parts require you to send them the gun for replacement.
Congrats on the M627T, it took me a while to find a good one.
I'm assuming I'm in good shape with my cylinder but check out pics 2 and 4 from top, the ones with the number "3" stamped on the cylinder. See the one cylinder with the two marks to the right of the "3"? These are not deep from what I can tell but does this look like cracking to you or just scratches from cleaning the face with a wire brush a long time ago, which one is not suppose to do?
And if the cylinder does go bad can I replace it with a steel one and are they easily available?