Hi,
The MAFAC-branded shoes on my Dural Forge (similar to Racer) brakes have a stud which is 7mm in diameter and 23mm long.
Sorry if this is bad news!
Chris Hughes.
According to the Raleigh Lightweight catalogue, the 1983 Rapide 12 has Reynolds 531 double-butted main tubes, Raleigh high-tensile stays with Gipiemme forged ends and Haden Olympic lugs. The fork material is not specified, but is presumably not 531.
Chris.
edit: the forks are specified as...