Flashing a Mobilepro 900 to 900c

I just got myself a nice Mobilepro 900 from Ebay. It has the HPC 2000 OS and bootloader 3.0 installed.
If possible I would like to upgrade the machine to Cmonex ROM 2.0
I checked out Cmonex's site and I hope I understand correctly:
1. I need to upgrade the bootloader first to version 4.1. For this I need to download the "official" NEC Rom with CE.net 4.2 and the updated bootloader 4.1

Here I am stuck since the download at Cmonex's website for the official ROM does not work.

That's the page I'm looking at (first download link):
http://hpcmonex.net/nec900/rom3.html

I don't have a serial cable and have to do it via CF card.

Any help would be appreciated.

Thank you!

Why didn't I find this with the search function?

I must be getting old My first computer was a Commodore PET - so that dates an old man...

Owned a PET myself, and a Superpet 9000 and a B128....good old IEEE 488 days...