I feel Intrisyc did the major hardware design of the iPronto. I had already noticed the similarities.
[Link: intrinsyc.com]
"The result was a solution based on Intrinsyc’s CerfPDA reference
platform and Intrinsyc’s CerfWorks device management software. The
CerfPDA reference design, modified to run Intel’s PXA250 processor,
provided the core of the hardware design and a significant portion of
the operating system adaptation for the iPronto."
Their I-Linux 4.0 CD contains sources and toolchain for kernel 2.4.17-rmk5-pxa1-cerf1. That's the version iPronto is running.