The last days of the /5 had a tank that had no space for a master cylinder but did not have the screw in emblems. They are rare tanks, I guess. I bought one thinking it had the space for a master cylinder on my /6 only to discover it did not. It did come with a nice /5 Aluminum gas cap. My plan is to some day beat on it with big hammers and make room for the master cylinder. Since this is a kinda iffy task I have not yet had the heart.
Never memorize something you can look up.