bikeworkshop
Old School Grand Master
I would like to thank you all for your input and I would think that the general consensus is to get the screw drilled out somehow, but I have no experience in doing this so I would personally not want to take the risk of doing this myself. I value these GT forks enough to not want to ruin them !
However, I have just remembered there's a bike repair shop in Sheffield, previously located in Dronfield.
https://vernonbarkercycles.co.uk/repairs_frames.html
I may take the forks there for them to have a look and see what they can do with it. I think for now they'll be the safest option for me to consider in order to make the forks useable.
Don't forget, the Forks are usable without the adjusting screw shank being removed.
It's pretty normal on a vintage race frame to just tidy it up and ride on.