Did you read the first post?
Yes, and I was following along quite nicely until I tried to answer your question--the one I quoted.
I'll try to answer it again.
Your replica revolver is certainly NOT a firearm
under federal law and therefore it is not regulated as a firearm under
federal law. It can be shipped and sold
under federal law as if it were merely a chunk of metal without any of the considerations that would normally be required for a firearm.
None of that has anything to do with whether or not it is a firearm
under TX law. Even if it were determined to be a firearm
under TX law, that would not affect the legality of shipping or selling it
under federal law. Furthermore, far as I know, TX has no laws regarding the shipment of firearms nor any requirements that firearm sales must be conducted through a dealer so it may be shipped or sold without going through a dealer
under TX law EVEN if we assume that it might be a firearm under TX law.
In addition to all that, the definition of firearm (and replica)
under federal law is different from the definition of firearm (and replica)
under TX law. So the fact that it is or isn't a replica
under TX law has no bearing on whether or not it is or isn't a replica
under federal law. As long as it's not a firearm
under federal law (and it isn't) it can be legally shipped and sold without a dealer being involved regardless of what TX says it is.