Simon, according to the book “RAF flying training and support units”, 3109 (Polish) SE was reformed 1.8.43 at Northolt to service 316Sq Spitfires; 21.9.43 took over 302 Sq Spitfires there; disbanded 4.10.43.

This book is really useful when it comes to deciphering unit abbreviations and locations, it is by Ray Sturtivant and published by Air Britain.

Very odd! I do have a copy of this book, and under the entry for ‘Servicing Echelons’ on page 271 it states ‘No attempt has been made to document their bases and histories in this volume’. My edition was printed in 1997, so is there an updated version?

Simon