I am restoring an old 386sx laptop that I bought as untested - its the same model essentially as my 1st ever PC.
It is an OEM'd Siemens-Nixdorf PCD-3Nsx (the actual model I have is an ICL NB386s and the original model I had was an RM NB300).
The packard bell 386NB version seems to be more common in the US

It has a number of, erm, quirks.
Principal among them is that the BIOS has locked HDD parameters - you can only choose 20, 30, 40, 60 or 80mb
Amazingly, the 60Mb drive works at the moment but I can't imagine it will last for long so I want to replace it with a CF card.

Being a laptop, there are no ISA slots so I cant easily get xtide going via an ISA card/network card
There is a ?docking connector on the back but I cant find a) any information about a dock or b) any manuals/service manuals/specs about it's pinout.
It is possible that it is, at least in part, carrying ISA lines but due to the lack of documentation, this is just a guess

I was wondering if I could append xtide into the actual bios rom - the rom is a socketed EPROM but I have a couple of worries about this:
a) I can't see a bios dump for these machines anywhere so if I nuked by bios chip, it'd be a problem! (obviously, I wouldnt overwrite the original chip)
b) It is a 27C010 which seems odd- my 486 bios is a 27C512 - a 1mbit bios chip seems very large especially for a 386
c) With the bios being seemingly low on options, is it likely it would support option ROMs?
The bios is an Award bios dated 1992 - "386 modular bios version 3.04d 01/28/92" appears on the POST screen

I dont have a EPROM reader at the moment that I feel safe using with this rom (I have a tommyprom EEPROM reader that I've used for xtide on 28c256 and to write 28c512s for my 486 but the 27c010 pinout is just different enough to be awkward and, again, I dont want to nuke it)

So, my questions are:
1. Is it likely that a 386 laptop award bios of this era would support option roms?
2. Are there any repositories online likely to hold this bios? I checked Retroweb but came up blank.
3. Is there anywhere that I can find documentation on the external 'dock' port to see if it carries ISA lines?

There are pictures of the motherboard, machine and connector here:
https://www.thenimbus.co.uk/range-of-nimbus-computers/nb300

But there is no detailed documentation.

Thanks for any pointers!