"One thing you need to know is that no matter which version you would get, it's NOT a Browning Automatic Rifle M1918. To get the blessing of the ATF, they had to change the operation from open bolt to closed bolt, the inside of the receiver is changed to prevent the use of the original action parts, and the trigger mechanism is altered. So what you get for your $5,000 is a gun that looks like a real BAR. I'm guessing you could find an Airsoft replica for a lot less."
1) Open bolt sucks, as anyone who has shot one knows
2) An open bolt 30-06 is even dumber (innovative at the time, whatever; it is not compelling now)
3) The semi/closed bolt conversion likely has a better trigger
4) It is not like original parts litter the street to be swapped in anyway (and would they even fit a vintage rifle that relied on hand fitting?)
5) Find me an airsoft replica that shoots 30-06
The gun is functionally similar, and a lot more practical than getting an SOT setup to build "real" facsimiles that are no more historical for such sticklers, and also can't be transferred easily/at all.
TCB