R90/6 1975 Final Drive number means?

[ottr]

I have a '75 R90/6 that I'm working on. I have the final drive off and there is a "46" and an "x" just below stamped on the final drive casing (on the right side looking at the brake shoes below the filler cap). Anyone know what this number refers to?
-c

[schrader7032]

I'm having a hard time visualizing what I'm looking at in your second photo. I think I see where the driveshaft bolts to the final drive and that seems to be the shaft fill plug on top. But I don't understand what the stuff is on the left side of your picture. Now if that plug is actually the drain plug, then I can see what it is.

I looked at my /7 from that same viewpoint...from the left side of the bike through the spokes...and do see some markings on the housing. I can see a "1" and something else...I'd have to remove my tire to see it.

That said, I don't think it means much. Might be something used on the assembly line in order to match a housing with a set of rear wheel splines???

[ottr]

Thanks. Here's a better view....
-c