The shaft is not where the seal is made in the speedo housing. The pic you posted shows the end of that shaft just sticking out of the housing. The seal is just behind the edge of the backing plate.
Search for FSM in the title of the classifieds. There is a link to a site with pdf copies.
Parts diagrams tend to be somewhat generic. Your SA 45 could have many different year parts on it. Search here for Venezuela, I think there are a couple threads about 40/45 assembly down there.
Is your 40 from South America? Based on Mark's observation, he thought 73 or older. If it's from SA it very well could be a hodge podge as you say.
Either way, you have to remove it. Maybe a 2 banana job. Then you can measure the stud and hole to what year will fit. As TPI's site says, you...
It's under the parking brake and handle section, page 2.
http://www.japan-parts.eu/toyota/us/1973/land-cruiser-40-55/fj40lv-a/4_791410_006_/powertrain-chassis/4601_parking-brake-cable/2#46501A
If you click on the part number on the drawing, it pops up a box with the actual part number.
This is one of my starting points for part numbers. Then you can search vendors here on Mud, online Toyota parts houses or your local dealer.
http://www.japan-parts.eu/toyota/us/1973/land-cruiser-40-55/fj40lv-a/4_791410_006_/tool-engine-fuel
I'm a "teach a man to fish" kind of guy ;)
The stud has a shoulder that sits flush inside the drum. Unless it broke, which is possible, it cannot come through the hole. It looks just like a wheel stud.