'Matching numbers' and such ... These days count as something like the Holy Grail. As an indication, there is something to be said for: Matching numbers guarantee that your classic with its original components is proud of your storage.
From the Vintage Bentley event, those matching numbers have been hot items for a while. Certainly because there are in the Bentley (and Bugatti, and Ferrari, and Porsche etc. etc.). cars and numbers are often juggled with. For example, even the same chassis / block numbers can pop up in different cars.
That wheeling and dealing is often done to make a 'replica' or tribute or to give a blunt clone more credible papers. Read: Make it more expensive.
And you can become a victim of that. Because a 'Real' is worth more.
However, there has been some breathing room in the Vintage Bentley world since in-depth research has shown that the factory itself considered chassis "just a" replacement part.
So that is a documented break with the idea that numbers should belong together. But no license to just pull the cut if you stand by your dream Bentley. In that case, consult first www.vintagebentleys.org
And that is nice to keep in mind if you want to buy / sell a Vintage Bentley.