If you consider the logic in place here, that it is important for collector value to have the engine that matches the car, but there is no easily available record of which engine went in each car, the question therefore becomes moot.
Add to that the simple fact that there are very few of these cars around, and entire engine swaps would be statistically rare because the typical problem of valve piston collisions do not require replacing the engine, just rebuilding the head.
What you get should be a greater concern that the head is the original one, not the engine block, and that the whole issue is probably unimportant since the data to show if the engine is original are not realistically available.
