How to check out Asterisk version that supports T38 Faxing?

I see that there is a trunk version of Asterisk that has code to support T.38 faxing.
I cannot to figure out how to check out just that version of asterisk, together with zaptel and libpri to get it all to compile happily.

Using svn -t 33890 … to get the asterisk version

but what trunk version for zaptel and libpri. There no trunk 33890 for these two modules and most others have massive compile errors.

Any one got a suggestion?