Hello batchit
There are some AUS companies that can reproduce
bottom blades to sample.

UK places should have info. on their files (without sample).
https://www.oldlawnmowerclub.co.uk/technical/spares/blades

The counter-sunk slot-head set screws are locally available.
I think these old Ransomes used double-row, self-aligning
reel ball bearings.

Cheers
----------------------
Jack