I got my receiver back from Orion Arms and while the engraving is top notch and job well done, he did not engrave exactly as I asked.  On the form 1 under any other makings I wrote my first initial, middle initial last name and the word trust.  When engraving he left out my middle initial.

Is this a big problem?  Or do I just need to send the ATF a note telling them the exact marking?  

So instead of:

B A Smith Trust
Mycity ST

It reads:

B Smith Tust
Mycity ST

What should I do?

Quoted: I got my receiver back from Orion Arms and while the engraving is top notch and job well done, he did not engrave exactly as I asked.  On the form 1 under any other makings I wrote my first initial, middle initial last name and the word trust.  When engraving he left out my middle initial. Is this a big problem?  Or do I just need to send the ATF a note telling them the exact marking?   So instead of: B A Smith Trust Mycity ST It reads: B Smith Tust Mycity ST What should I do?

I'd send them a letter.

I believe NFADan said that you should leave Any Other Markings blank, and that it actually is not for what you intend to engrave.  I believe if you read the statute on the engraving it says that it must clearly identify the maker and the city it was made, but nothing about it having to be included in that section of the Form 1.  In other words, I think you're fine, but you should check.  I'm not a lawyer and this is not legal advice.  Consult your doctor if it burns when you pee.

My paper work is still at the ATF, should I call them or just wait for it to come back then send a letter?

When I initially filled out the form there were many posts here some saying they left 4h blank, others writing in what would be engraved and others said they added additonal calibers etc.  So I interpreted the sentence "(Include all numbers and other identifying
data which will appear on the firearm)" to be what I would be engraving on it.  What a bunch of ambiguous BS.  Oh well, welcome to the world of NFA I guess.  

I put my engraving on the form and it was approved.  My engraving is also a little different, the engraver added "USA" after my city, state.  I haven't sent a letter or anything, I doubt it will ever cause a problem.