Is this Snowflake movement / case back legit?

[xeal]

Stumbled across this SF from a friend.

To my surprise, the watchmaker's tool could not remove the case back. It just happened to be loose enough for him to be able to open up with the classic ball that they use initially. Just find it strange that he could not use his tool on the watch, he can use it on other rolexes that I have got him previously.

Also on that note, are the case symmetries identical to a rolex, or is a 94010 slightly larger than a 5513?

Do the case back and movement look genuine?

Thanks in advance.