I don't think it would be too difficult to mount a plate on the firewall [where the M/C used to be] and connect the cable via a clevis to the existing pedal
Might need a tab welded on to it above the pivot so that it pulls the cable instead of pushing the M/C piston.
Here is how my B120 mechanical clutch is set up: -
Attachment:
Mechanical clutch geometry.JPG [ 84 KiB | Viewed 1724 times ]
Here is a possible donor, the N10 Pulsar has what looks like to be just what you are looking for: -
Attachment:
N10 Mechanical clutch (Large).JPG [ 51.74 KiB | Viewed 1722 times ]
I doubt that the normal hydraulic clutch pedal would require any strengthening but you'll just have to suck it and see