I saw this in Revok's blog. At first I thought it was just a childish argument with Fab 5 Freddy, a "supposedly" legend in NYC graff, but I've got to admit, Freddy's stuff kinda looks like Sever's...
Fred's (sever's S straight up bitten)
Freds (SEVER’s V upside down):
Fred's (Sever's R 45ºdegrees):
Fred's (Sever's E 180ºdegrees):
Sever's letters in detail: