Might I suggest you post your questions on the TEAE Facebook page and the Sunbeam Tiger FB page. They tend to get more action than our forum. Also easier to post photos.
Quick question for you…Are the original valve covers still on the engine. If so, there is a sticker one of the valve covers that has the engine number. That number should match the Number on the VIN. That is about as close as you get to matching numbers on a Tiger. You might also see if the casting date (the numbers near the starter) are in line with the the engine group number.
Has the Tiger you been looking at been TAC’d? That is another major consideration.
Lots of info for you at Norm Miller’s Website rootes1.com