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There were a lot of strange combinations assembled just before Schrade went out of business in 2004. These are commonly called "End of Days" knives.
Both Knives have a 3-9/16" frame so the blades would be interchangeable. However, the internal liners and assemblies with the Swindon rivets would be different. Unless someone took it apart and substituted the 197 blade and drilled it out to be a through pin, the 197 blade would have had to been attached to the three blade assembly for the 897.
If you see rivets in the bolsters, it is a indicator that the knife has been worked on and the blade replaced after it left the factory. If the entire Swindon assembly is still intact it was made that way in the factory. I would think that it is an End of Days knife, though I have not seen that particular variation myself.
As to the value, it's worth whatever someone will pay you for it. If the knife is pristine, there might be someone who is collecting variations of factory patterns from the End of Days. I don't think it's worth a lot of money but for somebody it may be worth a few more dollars.