Hola Marta...
Guess what...I just got a Centennial FW too! It arrived today and I'm so excited! I didn't know it was a Centennial when I bought it, so that was a nice surprise. It's a 1951 and it has the same, striated plate like yours, not the scrolled one. You definitely got a fabulous deal on yours. Mine is beautiful except for one serious flaw. It appears that it may have been in a flood and the paint is peeling away from the lower edge of the base. I'll post pix when I can. I paid almost exactly the same price as you did, about $161 and I didn't get a case, or accessories with it, so I really think that you made out! Yeah!
I'm going to hop over to Skip/Glenn's thread about redoing the painted surface on sewing machines. I think that I can fix mine to look pretty good with some advice and patience. Good luck with your new treasure!
~Cindy