@Bachgoro
Yes, my first phone is definitely a factory BROWN one as it came from ORANGE UK on a contract (actually 3 phones on 3 contracts) and all showed as BROWN when I did a Test Cable with DaVinci. I managed to get rid of 2 of them as I was told a BROWN phone is horrible to work with. The final phone I still have. Also it has a problem with the keys 1 4 7 and *. They no longer work. They used to. Of course I cannot send it for repair as it no longer has the original ORANGE UK software on it.
I followed the instructions on http://forums.se-nse.net/index.php?showtopic=7480 as it talked specifically about BROWN phones and I managed to update the FS with R1CA021. However, I think the old software on the phone was R1AA008. Is this a problem? I also noticed that when I used PhoneXS++ at the end it said that there was a difference in the IMEI and GDFS of phone name. The IMEI said it was a W800 while the GDFS said it was a K750. I wonder if the main phone was originally meant to be a W800 but Sony changed their mind and simply put it in a K750 housing and flashed a K750 software. The IMEI number starts with 359672.