Confusing advice from Infopass re: lost greencard and I-90

[Little_My 463]

So, here's the story: In November, my I-751 for removal of conditions was approved. My approval notice arrived, and a week later, USCIS mailed my greencard with a USPS tracking number. According to the tracking number, the card was delivered - but I never received it. I have talked with the local USPS office, placed posters around the apartment building in case it was delivered to someone else, called USCIS to make sure it wasn't returned, but so far there is no sign of the card.

I made an infopass appointment just to make sure that my understanding of the situation and my options was correct. I am eligible for citizenship application in April 2014, and I am traveling to my home country in February for a couple of weeks - and I was under the impression that 1) I will need to file the I-90 for replacement card (and pay the damn $450 for that joy) to get the I-551 stamp so that I can travel in Feb, and 2) I will need the receipt from the I-90 when I file the N-400, since I won't be able to provide a copy of my greencard (as I don't have it).

However, this is what I was told at the Infopass:

1. I don't need the I-551 stamp for my travel in Feb. Since I have the letter that extended my expired greencard by a year (until July 2014), I can travel with my expired greencard, that letter, and the letter that states that my ROC has been approved. They told me ( I was talking with two immigration officers) that when I return to the US, at immigration they will be able to see from the system that I have been approved for ROC and that I am a permanent resident, and that is really all they need. The expired card, extension letter and my approval letter will be enough to grant me entry.

2. This is the part that I was even more surprised about (and not sure if it is correct): I don't need to file the I-90 for my N-400. They told me that USCIS isn't out for people's money (hah.) and that if I don't need the physical card for anything else between now and April, there is no need for me to file and pay for the replacement. They said that when I file the N-400, I just attach a copy of my expired GC, a copy of my approval letter, and a letter stating that my GC was never delivered to me, and since they can see in their system that I was in fact approved for ROC and that I am eligible for citizenship, that's it.

Now, I don't know what to think - this is totally different that what I have been reading about such a situation. Of course, I am ecstatic if I do not have to file the I-90 and pay the damn $450 just a couple of months before I will be filing the N-400 - but I am a bit confused as to whether this is in fact correct or not... So, any thoughts and advice are warmly welcomed!