Another dumb question...1948 "turtle"

[34pickup]

My 48 coupe's speedometer did not work and in checking for the trouble I discovered that inside the turtle, the shaft that drives the cable was missing. Only the gear was inside it. So I ordered a new shaft and installed it along with a new cable and a speedometer gauge that I tested to see if the needle moved...it did.
Upon replacing the turtle, I noticed that it seemed odd to have the cable enter from the passenger's side, but thats where it was bolted when I first removed it.

So now, with new parts and turtle reinstalled with the cable entering from the passenger's side, the speedometer does not work. My question is; did the previous owner put the turtle on backwards? Should it go on with the cable entering from the driver's side? It fit this way but it may fit the other way around too.