Glen wrote:. . . The numbers you wrote above are IH part numbers, not the date codes that Cubs usually have.
Every Cub has the IH part numbers, the R in them is not a date code.
I think you are mistaking the R for the year 1948.
Every year of Cubs have the R in the part numbers. . . .
You didn't say if the Cub has a magneto, or a Battery Ignition unit.
I think you will probably prove to be right. I had taken the comment
Oldgoat wrote:. . . ALL of the castings are marker "R" = 1948. . . .
at face value. It would not be the first time someone has misinterpreted part numbers for date codes.
The first post in this thread does mention a magneto. But he may want to reconfirm that because of the fuse holder discrepancy. Of course, with an electrical system that has had some poorly done modifications, the fuse holder may not mean much either.