Hi, looking for ORB? or records at NA regarding Chain Home in Scotland. My late father flew as part of a private crew for ACM Sir.W.Mitchell in 1941 who, prior to his retirement oversaw the installation/ distribution of these. He flew under Station Flight-RAF Abbotsinch but I am not sure where to look for records as Scotland came under RAF 13 Group (also being No.11 Civil Defence Region) and possibly linked to No.72 Wing RAF. Any records I find on Sir Mitchel omit these details so I'm wondering if it is classed as classified?
Would appreciate any help, Fred