Timdo72

I would suggest you look at Vietnam embassy specific instructions. Maybe there is information there for you:
 
https://travel.state.gov/content/travel/en/us-visas/Visa-Reciprocity-and-Civil-Documents-by-Country/VietNam.html
 
Marriage
Non-Vietnamese nationals married in Vietnam and now seeking a record of the marriage should write to the provincial Justice Department (So Tu Phap)where the marriage/divorce took place. The request should include the date and location of the marriage. The Department will usually respond, but without friends or relatives to follow up, the process may be lengthy.
Common Law Marriages and Marriage of Relatives
Vietnamese law does not recognize common law marriages. Authorities do issue certificates verifying cohabitation but these do not constitute legal marriages. Vietnamese law prohibits marriage between blood siblings, half siblings, first cousins or any two persons related closer than three degrees of separation. The legal age for marriage is 20 for men and 18 for women.
 

First, NVC does not make the final decision on your affidavit of support.  Consular Officers do that.  If you use assets instead of income, NVC will tell you your income is insufficient, no matter how much you have in liquid assets, but they will still send the case on to the Consulate, where an officer will make a judgment call based on the totality of circumstances.
 
Have you read the definition of "liquid" from the I-864 instructions and find yourself comfortably qualifying based on liquid assets?  If so, why worry.  If not, study those instructions and do the math.

Then become an A-Student of the I-864 instructions.  You'll $3 in liquid assets to make up for each dollar of income shortfall.

Thank you and yes, you are right! I was confused. Now I understand that the 40 quarters only applied to the visa applicant and not the petitioner. 

Yes, sometimes the visa applicant has been in the US working previously.  See the words, "the principal applicant can be credited with 40 eligible quarters"  You are not applying for anything.  Your spouse is.  If you are unemployed, you'll need a job or a qualified joint sponsor.

I take it you are the "petitioner".  Petitioners submit affidavits of support for visa applicants.  If your visa applicant has 40 quarters of earnings, is the context.  Are you the petitioner, or visa applicant?

I think you are confused. If you are the petitioner, the American, you have to submit the I-864. 
 
When the beneficiary (the immigrant) works 40 quarters, or becomes a citizen, or you or she dies; then the I-864 is no longer enforceable. 
Yes. Once they work 40 quarters you are no longer responsible for them

***Moved from IR-1/CR-1 Process & Procedures to USCIS Service Centers forum.***
 
**Moderator hat off**
 
 
That used to be the case when only two service centers were responsible for adjudicating I-130 petitions.  In a nutshell, physical address of the petitioner became irrelevant when more service centers were given the task of adjudicating such petitions.

I believe they select based on case load.
 
Had a petition once in Texas Service Center, it was transferred mid-processing to California

We put deceased in both the city and country of residence and were approved. There's no requirement for the death certificate either!

There are cases where front loading a petition is advantageous.   But none of that matters to USCIS.  USCIS is looking to see if the parties are eligible to for the benefit being applied for.   Check the boxes and the petition will move on.  The facts are the facts.   NVC operates the same way - file the documents and show the minimum financial support and the petition will move on. 
 
Get to the consulate and things change.  The CO will take a few moments to look at the file before the interview.  The CO can consider many things.  Certain consulates are more difficult, like ISL and Morocco.  If you are from a country on the bottom 10% of the Passport Index expect it to be a rough ride. Are there red flags, like age gap, different religions, or where other cultural norms were not completed by the parties. Age and health conditions.  Will the beneficiary potentially be a public charge?  They are not required to look at or consider any documentation you bring in.  They can tell you they are recommending your visa for approval.  They don't actually approve you as the file is then again reviewed and security check are done.
 
So in some cases it is best to front load in the original petition with as much primary and secondary evidence as you can. Passport stamps, multiple trips, multiple charges on a credit card in country are best.  Pictures together, chat logs, boardings passes are secondary evidence.  
 
Immigration firms come in many types.   Most big firms are doing work based visas.  H1/H2/L/O is where the (easy) money is made. They tend not to do a lot of initial family visas.  Family visas take a lot of time to do right, have lots of emotion and there is a lot of hand holding that gets done.  Ironically most family visas are the easiest DYI.   
 
Do you have a good attorney?  I don't know.  Their yelp review is about half O-1 visas.  It boils down to if you think they did a good job filling out the forms.
 
I doubt there is going to be an issue with the USCIS.  The consulate is where all the fun is!

That is usually for the intending immigrants. Your birth certificate would be useless even if you have it for the purpose here, so don’t worry, you are fine.

The requirement is to show that you are a USC. Both documents provided accomplish that.
That said, I'm assuming a BC or the affidavit was provided previously in your immigration process...

I thought Dairy Queen  

If you didn’t get married until 2020 you would file 2019 taxes as single. 

We have always used USPS priority (it includes tracking), for all three petitions (i-129f, AOS and ROC). Has worked like a charm, and would it them again if needed.

Personally, I always use USPS Priority Mail........it gives you a tracking number, and it usually arrives in 2-3 days.