I wouldn't be too eeked-out over adjusting toe-in with a wrench like that. It is a common thing to do and we did it all the time in the 70's to stop squeal.

With modern brake shoes you are going to find that the metallurgy of the vintage Raleigh brake components are not up to par with the forces that will be achieved. Things are going to bend anyhow if you brake really hard. I had to put the little angle-bracket bits back into the rear brakes that transmit the force into the wheelstays to keep the rears from self-destructing and the fronts can't be helped so be prepared to bend something back from time to time -especially the mounting bolt which may just bend up with the brake if the brake calipers are wore where they pivot so they don't hold it perfectly solid over the pivot. The brakes caliper arms themselves will tend to bend a bit too.

The kinds of braking forces that modern pads can generate are well beyond what the original Raleigh engineers could have envisioned at the time they designed them. Add in alloy rims and we up the ante even further over steel.