Hi,
According to the Cub parts manual, the original starter switches for the first several years of Cubs was a sheet metal switch, up to serial number 128798, which was during 1951.
Then they changed to the die cast switch, until the end of 6 volt starters at serial number 224400.
Below is a page from the Cub parts manual. You can read at numbers 2 and 4 what it says.
The long starter lever was used with the sheet metal switch, and the short lever was used with the die cast switch.
http://www.farmallcub.info/manuals/cub_ ... 008-09.jpg
So a 1947 Cub would have had the sheet metal switch, the manual says.
They evidently quit making the die cast switch, and make the sheet metal switch again nowadays.
I found info in the Cub parts manual TC-37D, from 1954, that they changed the starter model number from 1109603 to 1109611, at serial number 128799.
The link for the page does not work when I post it here.