Two Sets of Fitted Barrels

[B. Dudley]

You would know right off the bat if the extractor barrels, if that is what they are, will physically fit the frame or not.
Likely they will not fit 100% if the gun was converted to ejectors. Since as I mentioned above, the roll joint would have been changed to the ejector type. This possibly throwing off the fit.
Those barrels would likely be able to be fitted to the frame, and be made to be used as extractor barrels. However, this would require you having an extractor forend, and also slots will have to be milled out in the forend iron to be able to clear the ejector trips as all will work correctly.
The only other issue that will be faced is that with the extractor barrels, the shells will
Not be lifted out as high as normal, making shell extraction with the hands a little more difficult. This is because of the fact that the ejector roll joint is of a different design than the extrator one.

There are a lot of unknown scenarios here. Best to get the gun and figure out exactly what you are dealing with and then figure out what you can and cannot do.