1950's GLB Spec

[driftLimiter]

1951 School Classroom Building. I have a scan from the owner of the original construction drawings. For whatever reason the text of the GLB specification is very faint (as if it was added at the last minute by the engineer instead of the drafter).

So I have two issues first is I can't really read it and have to assume what it is saying.

Second, every assumption I make seems to come up empty with google searches.

Here is a snip of the callout.

To me it appears to say

NCLA Exp. C Specifications Combination #6.

Italic text is not shown in the imagine but sits just above the 'NCLA' callout.

Does anyone know what this callout is telling me? I feel like it is lacking material type callout. Perhaps its in project specifications that I don't have.
Does anyone know where GLB's were specified and graded in the 1950's?

I tried some wayback machine on SlideruleEras website but that didn't really lead me anywhere useful. Also tried to 'Enhance' this image with little success.

I feel like if I could get some idea of what 'NCLA' means and find some documents from back then I might be able to make some assumptions and proceed.

 

[jerseyshore]

Some googling has led me to find that it was standardized in 1952 by the AITC.

So before that it'll seem info is harder to find. What state is this school in? Seems like prior to 1952 Forest Products Laboratory and Unit Structures did most of the glulam builds.

 

[jerseyshore]

Also there is an old thread on this page where people suggested to contact AITC. Looks like all of those other web links are dead.

https://www.eng-tips.com/viewthread.cfm?qid=197771

 

[keyepitts]

No idea really, but could it have been meant to read- "NLGA", Nation Lumber Grading Assoc?