I could I suppose buy a new AGP graphics card - the voltages changed at some stage and I don't know whether the old ones are the low voltage or the high voltage. They are still listed in computer mags like MicroMart. I do have a spare graphics card, but it is currently in use on my Athlon 2000 machine because there for some reason the onboard graphics would only let me see 16 colours in 480x640 (not very useful). I don't have a scrap graphics card - but WAIT! I have two scrap motherboards both with onboard graphics!!
That might be worth a try! The nVidia is worth saving as in 2000 it was a pretty punchy card with an onboard processor and memory - or I could spend £20.
Option 2 is I have a friend who has lots of scrap computers and he might have an AGP card if I could find the drivers on the internet.
I could also modify a lead by putting tiny blobs of solder on the pins in the plug to make them a tighter fit...
Fiddly....
Option 3 is to get a newer PCI card (but not too new in design for compatibility reasons) as the motherboard has oodles of PCI slots (currently it sports 2 modems, one of them on a funny slot that might be an AMR slot, a network card, the graphics card, and a TV card, and still 2 PCI slots spare). I ahve my eye on a soundcard too, and then it would be all slots full. If I achieve that I might have to mod and light the case.....