I am not qualified enough on this subject. So far, by your information by leaving Poland before 1918 they would not have been viewed as having citizenship from there. During their stay in the U.S. did they ever file for citizenship before returning?
Your best bet would be to try and get any and all documents you can starting from the time they entered the U.S. After that, it would be the same issue with going back to Poland such as documents from where they lived after moving back after re-establishing themselves.
Also, what can you obtain on military records for the family member in question? By getting these will also help to provide you with a timeline and some history on the family. Also, by checking the citizenship acts of 1920 and 1951 will be a bit confusing at first, but will help to determine how easy your case will be.
When your parent(s) came back will determine which act will be relevant to your case. Then the other issue would be how long did this person have to wait after entering the U.S. as a landed immigrant before being able to get citizenship (naturalized)? If this overlapped the 1951 act by the time you were born then you will have to determine how this may help you. Sorry I am not of much help, but I hope this gives you a start. The main thing is to get any and all documents you can and make sure they are certified. Whether you think these will help or not, will give you a timeline and help to establish the facts you want of the whereabouts and citizenship of the people involved. Good luck.

 

I am not sure how much it will cost singly (for your mother first) or as a group. I am not the right person to ask that one. You would be better to ask a lawyer that handles such cases. If I was a lawyer, I would take you as a group, but I would present your mother's case first since the claims of citizenship for the others depends on hers. Lukasz Piotrowski would be a good person to ask and handle your situation.
Have you looked at the 3 parts for confirmation of citizenship? While it is confusing to start with, but there are others like yourself, that have dealt with similar situations. As I have said before, try to get all the documents you can whether they support your case or not. Such as entering the States early in the 20th century, anything to support the return and consequent living in Poland, military records, passports that were issued from Poland, if any, other documentation, such as that from the International Refugee organisation in lieu of an issued passport. A gentleman by the name of Curious George made a posting of the paperwork that would be needed. Ask him if he can link you to that posting so you can print it out so you can use it as a checklist.
If you understand a flowchart in regards to computer programming, you will be able to understand and follow it and it sometimes goes back to certain points on a negative answer to a next point. I am not sure how easy or long it will take to get a passport. You may also need to get a pesel before you can get a passport. As for knowing the language, either a basic understanding or fluency level would help, but I am not sure it will be relevant. Hope this helps.

 

I have heard (read) of horror stories where the original documents getting lost or accidently destroyed while en route to the destination. Or when the documents actually arrive, they go missing or get misplaced.
So, my best advice, and I could be wrong, get 3 or 4 copies made of all the originals that you have and get them notarized. Chances are it will not cost all that much more to get the extra copies done at the same time rather then later. Then if the copies that are sent off go missing somewhere and you are requested to send another set, then you are prepared for it.
Even if the extra copies are not needed, it makes it easier then to store the originals in a fire proof box for safe keeping. Then you can always use the copies for future handling and research. Good luck.

 

That is going to depend on the Polish Consulate or Embassy in your area. Most documents such as where they come, state archives, will probably already have an official stamp from the appropriate office. So, in most cases that will be acceptable. But you may run into someone who may nitpick and expect the documents to be translated in Polish before they will be accepted.
Sometimes, that is where other copies come in handy. So, let us say the consulate wants the documents translated. Then you may as well get the documents you have copied and notarized then translated into Polish and those notarized as Translations of the English copies. Then you can submit both copies. But since I am not a notary public, lawyer or someone who works in the consulate or embassy, best check with them. Also, did you go over the list that Curious George made?

 

I wouldn't say great insight. I did read parts 1 & 2 as well as 3. That is how I knew about the posting that Curious George made about the different documents. I am also going through it myself. But my case is a bit more complicated since I am having some problems trying to locate some documents and putting it all together in some sort of biography that may be required.