If you want to make a Whatley, it would probably have been walnut. However, I can assure you there is no real difference between European beech and American. I wanted to replicate a Carolina Gun and no supplier had any beech - euro or otherwise. Yet a sawmill close to me had a huge slab of it. Many of the cheaper Belgian guns used it. However - I have not tried it - but someone here said you can simulate european walnut by using a yellow dye on American walnut. And true, getting a bland straight grained european walnut blank would probably be harder than getting a nice piece. My next gun will be a Northwest Gun of the 1812 era, and I have a slab of black American walnut set by for it. I'll experiment with a yellow stain to make it more resemble English walnut.