Peter, good morning.
A book about KG 30 would be really wonderful....Wish you will be successfull.
Have you passed your eyes through this:
https://discovery.nationalarchives.g...ails/r/C387330
https://discovery.nationalarchives.g...etails/r/C1908
https://discovery.nationalarchives.g...e/r/r/C573281?
I believe the Files are there at TNA...one just need to know how and where to find them. There may be more, of course and I do hope someone with more expertise will be of assistance.
Wish all the success the project deserves and wish to be able to read KG 30 History one day from you.
Adriano