Q:

LGHT0311 error on RTF file to be shown in licence dialog

Have a .wxl file for pt-BR and codepage 860, for some reason the included wxl file for the rest of the wix UI for pt-PT and pt-BR are using codepage 1252. 
C:\delivery\Dev\wix35_public\src\ext\UIExtension\wixlib\LicenseAgreementDlg.wxs(35) : 

error LGHT0311 : A string was provided with characters that are not available in the specified database code page '1252'. 
Either change these characters to ones that exist in the database's code page, or update the database's code page by modifying one of the following attributes:
 .  Product/@Codepage, Module/@Codepage, Patch/@Codepage, PatchCreation/@Codepage, or WixLocalization/@Codepage. 
The line in error is where it reads in the content of the rtf file. 
I found the suggestion of setting Product/@Codepage="!(loc. CodePage)" however it appears in 3.5 that you can't use a localisation for that attribute. 
At the moment the other 12 languages all work including ja-JP, zh-CN, es-ES. 
Options I'm trying to work out:

Is there 1 right codepage for pt, or pt-BR? 
How to tell what part of the text is not in the codepage?  How can I point out the text in error based on either codepage 860 or 1252 (whichever is appropriate). 
How to easily set the codepage rather than having to rebuild the product each time? 
How do I tell wix not to use the built in wxl (and codepage) and instead use the one I want? 

A:

In trying to work out how to tell what part of the text is not in the codepage I loaded the rtf document in WordPad and saved it back out.   The WordPad saved version of the document appears to be acceptable to WiX. (substatntially different raw data text and smaller)
Just have to check the content didn't actually change.