I have had Shimano 600 set waiting for build. I have been searching Peugeot Puymorens which has Reynolds 531 Professional Tubing. Frame I managed to find was equipped with Reynolds 501 Fork. I have been looking for 531 fork, but no success yet. I have NOS super Vitus fork with lion engarving in crown, it could be best alternative in 531 does nor appear from somewhere.
Even the saddle is black, I might try white bar tape. It is more original than black. I have Orange cables when original were grey. But they are easy to change.
Puymorens pictures from 1987 catalog