Sorry, fellows.
Just put the 8372 (A if NTSC or B if PAL) in the socket to be able to deal with 1 Mb ChipRAM. Oh, and that damm strap (J500, I think)must be closed.
Need a very hard hacking to give the 2000 hability to manage 2 Mb Chip (8375 Agnus, modified Gary, some ttl hacks, etc)