I'm sorry to say that I think your student's original letter is a better one than yours; chiefly because it is not necessary, when writing in English, to embellish sentences with phrases like "It is pleasing to..." and "It was most honored to ..." [which is also wrong grammatically]. Also, when writing such a letter, you will have put your new address at the head of the page, so there is no need to tell Mrs Smith about it again - she will recognise it as a new address. Finally, even in a formal letter, you would address a good friend by her first name.
I would write the letter as:
Dear Ann [or Dear Mrs Smith - no need for a full stop after Mrs}
We moved into our new home a few days ago, and I would like to invite you to a celebration dinner here at 7pm on October 4th. Please let me know if you are able to came. I look forward to showing you round the house, and introducing some of my other friends to you.