David:
I cannot answer your question just now, but.......
A most Happy 50th Birthday
How appropriate, you were born the year I first started collecting stuff on soft skins, hanging out at the Motor Pools on various Marine Corps Bases as a callow 15 year old. Thank goodness, I was at the time "The Colonel's Son" and most of the Motor Transport Sergeants were quite generous with old Tech Manuals and the like.
And now here we are, me celebrating my 50th year collecting and you your 50th Birthday.
Many Happy Returns.
Bill