Jim Burns wrote:

I found some completely packaged boxes in another wooden crate, these boxes
have the MS part number on them, but the bolts only markings are the A or
the L, non of the other markings.

In the AN world, having no hash marks on the head indicates low-strength steel.
Now, my info is coming from an elderly copy of AC 43.13-1A. Perhaps your bolts
predate the adoption of that marking scheme.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.