Looking for build plans for a colt python?

Generally patents aren't indefinite. Otherwise there would be no 1911 clones or Beretta 92 clones. You probably couldn't make it say colt python on it but you could give it the same look.

No idea where you'd find the build plans. I wouldn't suggest it unless you were a skilled machinist either. Hand tooling guns makes for very rudimentary firearms that are glitchy at the best of times exploding parts at the worst.

Not only would there likely be copyright infringement issues, but you would probably have a pretty hard time acquiring all the parts necessary to build one, even as a non-firing but working replica. Have you ever seen the mechanism that operates a revolver? The tolerances are far tighter than you could likely handle in a high school or tech school machine shop.

And perish the thought of trying to build a replica that could be fired... Unless you have lots of money and appropriate materials, don't bother... You'd probably be building a hand grenade shaped like a Python.

You think a company would post the plans for their products on the internet? Think about that for a minute.

There would likely be a few trademark and patent violations involved if you did it.