Ed I don’t know about the ’49s but the earlier two I have, have a two impeller aluminum deal. My motors could be a mix and match. Meaning they were the same for so many years that parts might have gotten mixed up. When they run they are quiet and smooth. Very important to keep the fuel clean! This picture shows the difference in the transom clamps and the twist grip. One gas tank is tin the other is cast aluminum.
good luck with yours
dale
