Hi Richard....No offence taken, no worries.
As I see it, in the short term all options need to be kept open. Butchering the frame takes away the possible original unmolested status, as does adding a pedal pivot support plate. On the face of it swapping the solid S/A solid spindle for a hollow one (Assuming the OD is the same) would allow the use of the bore as a pedal pivot. Then modifying the brake pedal for rod or cable means the bike becomes useable with the option to change back to the original type of full width hubs as and when. The long through shaft will give lots of support, compared to the Slack Alice sideways movement of the pedal, as found on a typical plunger frame.
At the end of the day it is the owner's choice, I just offered my suggestions in the light of my experiences.
OK Matt, decision time.....(maybe)
Swarfy