Hello STEW1957,
A couple more pictures to show how a well worn chassis can look. Your one actually doesn't look too bad considering but will give you some good practice on rebuilding these chassis.
A new axle measures 4.55mm for the large journal and 4.09mm for the small journal on my micrometer if you need some reference data.
On the bottom picture the large journal hole measured top to bottom at 5.12mm and 5.55mm left to right.
Before you start to reassemble it back again let us know how it goes and I'll go through how I cleaned up the axles to remove as much scoring as possible before I got a supply of new axles, it isn't what I would call good engineering practice but then I had no other options back then and it did work.
Below is chassis showing small journal
Below is the large journal hole, again seen better days.
