The od of the seat tube of the Sears bike I removed it from is 28.07, and it fit well on that bike. The od of the British bike I put it on is 28.6. The Id of the fd clamp is 27.2. I forced it on and it spread open enough. It scratched the new paint though. I'll have to touch it up.
I do need to replace the nut and bolt with a proper one, and install the new cable and it will be done.