Fuck, seriously, as with every other question you've felt the need to ask, in less than a minute, I found the answer. Learn to use google.
Since you're too retarded to do your own searches though, "open wide, here comes the airplane!"
C1A1
http://www.eme421.com/FNC1A1.html
http://www.milsurps.com/content.php?...A1-vs.-FN-C1A1
http://en.wikipedia.org/wiki/FN_FAL#...h_pattern_FALs
L1A1
http://en.wikipedia.org/wiki/L1A1_Self-Loading_Rifle
FN FAL
http://en.wikipedia.org/wiki/FN_FAL
EDIT: As far as turning an airsoft FAL into a C1, your MAIN challenge, other than trades, will be wood furnature. As far as trades go, unless you can get a bank lower, you're out of luck I think