Im 28 and have a lifelong interest in military vehicles, my first ever rally was at the age of 3 months in a AEC Matador. Ive been involved in countless restorations from Diamond T's, to Morris 10/4 staff cars. I own my own Austin K9 and I helped my brother age 22 restore his Bedford RL.
I think the subject of green machines is enough to keep 'new blood' entering the hobby, but some of the attitudes of the club members and rally organisers are whats causing harm to the hobby. For instance, rallies where post war vehicles are not allowed, where you can go and see line upon line of jeeps (usually 60's French ones marked as wartime) yet they wont let me in in my K9 or my brother in his RL.
I was a member of the MVT for a few years, I enjoyed the mag but didn't really get anything else out of it, saw lots of politics and groups splitting and joining other areas, I can remember one monthly meet I attended had more people talking about washing machine recommendations than military vehicles or restoration. So when my membership ran out, I didn't bother renewing, I know at least 5 younger MV owners that feel the same, sadly.