Leo: normally these chips are soldered directly onto the mainboard. Either this, or the computer must have been modded by a die-hard MSX-modder who wanted the system to be easily upgradable. Your chance is little, I'm afraid.
Hehe, the only bid: by Konamito
Guess I would not be making friends by overbidding him ...
Anyway, the seller lives in Hoorn, Holland; that's 7 km from my home.
There are quite some active MSXers (i.e. Repair-Bas, Latok, BiFi) in the area
and MCWF (MSX Club West-Friesland) too.
@Konamito: I'm not gonna buy it, so don't worry
In case the deal goes bad I wouldn't mind asking around for a 8280 for you,
if you wish ofcourse ...
I made the bid before I read the entire article (I was so excited) so after I made it I realized that this guy only sells in Netherlands. I´m from Spain so I don´t know how the thing will come out. I´m very interested on it but I don´t know if he wants to sell outside his country.