That's exactly the same , think your SB is about 6 numbers less than, my dyna tech was Gary coltman s , so pretty special and very rareHere's a 1990 team bike..
My bike SB is 9447. And exactly the same , but stamped G.C B2 91 , incredible it is only 3 numbers different .it also has all the correct dura ace 8 speed groupset and wheels , on GP 4 tubsNot my bike but belongs to another Retrobike forum member, great bike you have there btw , looking like it's got all the original components as well..
Thread 'SB9443 Team Owned Raleigh 753 Dyna-Tech Castorama' https://www.retrobike.co.uk/threads/sb9443-team-owned-raleigh-753-dyna-tech-castorama.329993/