On the invoice I've got when I received my phone, it states Country of Manufacture: Hong Kong, if that helps. I'm trying to flash that unbranded LPG firmware as recommended without luck. In fact, ODIN has been hanging on NAND Write Start for the past 30mins as shown: ODIN-1.jpg download - 2shared
My SGS2 is definitely not a variant of I9100 and the box looks exactly like this one pictured:
My phone also came out with Gingerbread although I'm not sure which version :S perhaps 2.3.4 but it may have been 2.3.3, I can't remember.
Would the IMEI no provide any assistance? Also, by trying to flash the stock LPG firmware, does it need to be the original firmware the phone came with? That is, Gingerbread rather than ICS firmware?