Marine blocks

I've got a 400 blk in time period of the cold wx blocks
From June 71-Dec 71, or so I've read

I'm trying to verify
By any pics
Of the block webbing which is noticeably different than 400 std

I ve done lots of research and found pictures now I can't remember

Any info ????
What exactly does that have to do with this thread? You should probably start your own post and not muddy up this one.