Well I don't get it you want to debrand your phone so it is like when you bought it? So you own branded phone or not?
I think if you want to debrand you just figure out which language that you need and use Generic MAIN and corresponding FS and custpack that have your language in it.
For example if you are on vodafone/02 and live in England then just choose GENERIC MAIN and any European FS and custpack as it all has English languange. If you live in spain you may want to look which one (of the European FS) that has Spain language, etc. Just make sure the FS and custpack is the same otherwise your phone will only show English (as default).
Where do you live anyway and what language you want to have in your phone?
If you live in ASIAN region, the MAIN will probably CHINA and then you choose FS like APAC (Asean), specific Thai, etc. If you are in Hongkong and Taiwan they have their own MAIN and FS (because they use different chinese writing than other CHinese like Mainland China/Singapore)
Well, if you have CID49 then the newest you can install probably R1ED. You may want to use SEUS to upgrade your CID to CID52 first before unbranding using the newest firmware with XS++2.2 or SETool lite 1.08.