How to proceed for Linitx/LEX Computech/Infineon Danube ADSL2+ PCI missing files?

I'd like some advice on how to proceed promptly to resolve some issues 
I've discovered with an incomplete source-code distribution.

In the U.K. I recently purchased from Linitx a PCI ADSL2+ PCI adapter 
for a gateway server. The device has an embedded Infineon Danube MIPS 
SoC which communicates with the host via an Ethernet port. The embedded 
device runs Linux with uclib and many common GPL projects including BusyBox.

The retailer supplied a source-code archive when I emailed a request.

I've subsequently found that the source-code bundle has two issues:

1. Missing the u-boot 1.0.6 Infineon-specific source-code which as far 
as I understand from checking the strings is GPL-licensed.
2. The included busybox source fails to build since it is missing an 
Infineon-specific header file "ifx_config.h"

I emailed Linitx regarding (1) and they replied saying they've passed my 
enquiry to LEX Computech who should contact me directly. I've not 
received any communications from LEX Computech so far. I understand that 
Linitx are at the mercy of their supplier and device manufacturer.

Today I discovered (2) and have sent another email to Linitx reporting 
the missing file.

Obviously I want to be in a position to build the complete GPL portions 
of the firmware. My main aim is to add pptpd to the rootfs but I'd also 
like to be able to update the installed software where necessary.

I've been documenting my exploration of the device and provided software at:

http://tjworld.net/wiki/Linux/Embedded/Infineon/Danube/ADSL2PCI

Any advice would be appreciated.