Which market?

Packard Bell had very different model numbers - and CDs for the different countries they were active in. There are definitely Master CDs after 1999 online, up to mid 00's here:
https://archive.org/search.php?query=packard+bell+master+cd
- just almost certainly not the one you are looking for.

If this is Europe, there were two releases with WIn98SE, the late 1999-mid 2000 'Symphony' with part numbers - including MasterCD part numbers - starting with 676. From late 2000 onward until the move to eMove (green translucent styling on the PCs) and WinME, the last WIn98SE systems were 'Symphony2k' with part numbers starting with 678. If your estimate of the age of the system is correct, it would be SY2k. You can check this by looking at the sticker on the back of the computer - it will also have part numbers in either 676 or 678 range. Your CD will be in the same range as the case.

Now, there were multiple revisions of the master CDs within each release, and the tricky bit is that your CD would only work if it was at least same age as hardware or newer. Finally there were different languages. 01 was (UK/IE) English, 05 was NL.

I have a document which suggests that Symphony master CDs have a P/N starting with 676793xxyy and Symphony2k starting with 678519xxyy. xx=version, yy=language. So assuming you want the oldest UK English version of the SY2k master CD, it would then be 6785190001, with the next version being 6785190101 etc. Just one problem: there's no record anywhere I can find of those part numbers on internet. I suspect I know why: these are the internal part number for the CD bundle, not the separate part numbers for the CDs themselves. I'm sure I once knew how to derive them (which is why I didn't even bother to document it), but that was over 20 years ago and I unfortunately don't now. I'd recommend looking generically for Packard Bell Master CDs in your country and if you find them (invariably without P/N listed) looking for the 676/678 first digits.

The CDs looked very similar to this (slightly newer eMove) set https://archive.org/details/mastercds.7z

Ah sorry, UK region. The master CD I have from back then is labelled 6767910501 - but is detected as the wrong master CD when attempting to restore, so I suspect you are right I need one just a little bit newer for this one. I did take a look at I think the tattoo info on the machine, this is it -

Nothing too fancy there in the hardware config, that Houston motherboard had been used since Intel first vomited up the i810 chipset, and it was paired with the MR2800 AMR modem (probably not top of list of things you want to get working 😉 ). That's about it, the SigmaTel audio is integrated AC'97 stuff -it's about the most basic low-end config out there. Can't imagine it's impossible to get it working with a not-so-old Symphony CD.

Is the HDD original? If not, try booting from master floppy, navigating to root of MasterCD, then EXTHS /RESTORE followed by TATTOO /CREATEDMIFROMHS. If that works you know you have hidden sector and DMI that correspond to the CD you own.

HDD seems to be the original, with the tattoo stuff on it. If i run the EXTHS /RESTORE and TATTOO /CREATEDMIFROMHS commands, will that overwrite whats on there, and then it should allow my old master CD to work?

And I love my old basic PC 😂

Well, it did! Only thing that didnt install were the onboard sound drivers, but I have put in a Sound Blaster PCI (I think the same one I had back in the day) and all is well 😁 Now to find my GeForce 2 MX .....

BoozerDawg wrote on 2022-03-05, 22:51:

Well, it did! Only thing that didnt install were the onboard sound drivers, but I have put in a Sound Blaster PCI (I think the same one I had back in the day) and all is well 😁 Now to find my GeForce 2 MX .....

Good job ! Which master CD did you use ? Just curious....

Horun wrote on 2022-03-06, 00:17:

BoozerDawg wrote on 2022-03-05, 22:51:

Well, it did! Only thing that didnt install were the onboard sound drivers, but I have put in a Sound Blaster PCI (I think the same one I had back in the day) and all is well 😁 Now to find my GeForce 2 MX .....

Good job ! Which master CD did you use ? Just curious....

I used my original Master CD's I for some reason kept from 1999/2000 ish, 1st being labelled 6767910501 and second being 6767920501 (the sticker on the case say they were made on 20/11/99).