The Home Guard were commonly thought to have comprised mostly of men who were too old to serve in military service, yet The National Archives pilot project has revealed that 50% of the records selected for the project, were of men under the age of 27, with 28% of the men aged 18 or younger.* http://www.nationalarchives.gov.uk/documents/home-guard-press-release.pdf
I wonder if they changed the laws for conscription (age, fitness) as the war became longer and more destructive of human life as it went on? As in Germany. My MGF was in the home Guard. He would be in his 50s.
My father was a member of the LDV/Home Guard in south Manchester from 18 to 21 when he was called up into the Army. When Dad's Army started he told me some stories of his Home Guard unit which meant I watched the series as a documentary and not a comedy. Guarding a bridge armed with 5 rounds of .303 and a .300 rifle comes to mind.
Not sure how accurate the article really is. At the beginning, many - if not most - volunteers were WW1 veterans/older men. However, after February 1942, these were often weeded out and younger 16-17 year olds conscripted into the HG as preparation for army service. This is often reflected in 1944 stand down group photos which often show a large number pale-faced youths amongst the ranks.