Besides the extension, are 30/31 front fenders the same?

[steve hackel]

I am not sure, so asking the experienced restorers this question;
besides the short splash extension that is welded to the 1930 front fenders, are the fenders actually the same? Both my splash shields are gone at the running boards, and also at the front fenders extensions. I need to replace the running boards, the splash shields, and also the short extensions; if I just remove the extensions and then repair the fenders at that point, I can just buy the longer 31 splash shields when I buy the running boards and assemble it all as a 1931. Is there anything I am missing from my observations?
Thanks, Steve