the N28F010 contents seem to have some odd bit errors.
just a quick glance at the contents shows several mentions of 'memorx' which I'm fairly certain should be 'memory'

Can you describe how and what equipment you used to read it out and read it out again after cleaning all the contact surfaces on the chips and the reader.

It is likely that the BIOS is split bytewise into 2 ROMS. So you'll find a string "ABCDEFGH" into 2 ROMS: "ACEG" and "BDFH".
This is often used in 286 and 386 SX / SL systems because the penalty for an 8 bit BIOS access would decrease performance if the BIOS is not shadowed.
Which CPU is in it?

Correction: It looks like a system BIOS and a VGA BIOS.

Actually, both BIOS dumps are obviously unreliable. The small dump most likely should read "Copyright SystemSoft Corporation, 1990-1991." instead of "Bopxrhghp RxrpemRobp Borpor`phoj( 0880(0880*". Bits 0 and 2 (values 01 and 04) are bad. This looks very much like a contact problem to me. As the dump of the big ROM contains similar errors, I suspect that the PLCC32 socket in the reader is correded and doesn't make sufficient contact to the ROM chips. If you use an PLCC32-to-DIP adapter on your reader, the issue might also be a bad contact between the adapter and the reader. Probably the issue can be fixed using contact cleaner and mechanical scraping.

There is no reason to assume bits being swapped or bytes being interleaved given the data in the ROM files. weedeewee already pointed out that the big ROM dump contains similar issues. The start of the big ROM dump is the graphics BIOS, which is 32K. As a legacy EGA/VGA detection algorithm is looking for the string "IBM" in the video BIOS ROM, the graphics ROM is supposed to contain "IBM" at 1E, but this dump says "HBM" instead. Furthermore, it is supposed to read something like "SystemSoft Cirrus 6225 SGD BIOS "<CR><LF>"Copyright 1992 SystemSoft corp. - All Rights Reserved"<CR><LF> (not sure about the "SGD" part). but it reads "RxrpemRobp Bhrrur 2225 RG@ BHOR "<CR><LF>"Bopxrhghp 0882 RxrpemRobp Borp* - @hh Rhghpr Rererre`"<CR><LF>. I don't know what the second 32K of the big ROM dump are for, but the final 64K are the standard mainboard BIOS.

The small ROM might contain power management firmware (if the processor is an SL-type processor with system management mode - a 486SLC would be an obvious choice for a laptop like this) or fimrware for a keyboard/system management processor.

I don't see any obvious signs of addressing errors, so it's "just" two data bits that are bad.

Well, actually, it doesn't look like a bad contact, but like a short between data bit D0 and data bit D2. Because TTL chips (and TTL-compatible chips) are stronger at pulling an output low than at pulling it high, this will result in D0 and D2 always having the same level, which is low if at least one bit of D0 and D2 is low, and high if both are high.

I hacked a JavaScript font viewer that you can use to look at the VGA fonts in the VGA BIOS of your dump. You will see that all the characters are present, and that bad bits are always in the same columns, which again clearly shows that addressing works, but some specific data bits are wrong. You can use that tool by visiting https://karcherm.github.io/fontview/ To look at the fonts included in your ROM dump, use the button next to "Use part of local file" and click the "Browse..." button (your browser may use your native language instead of "Browse..."), and select the 28F010 file. Some new fields will appear. To look at the different fonts, use

• Start = 0x4502, Height = 8 for the 8x8 font
• Start = 0x4D03, Height = 14 for the 8x14 font
• Start = 0x5B321, Height = 16 for the 8x16 font