I found a Win98 bootdisk, ran fdisk /mbr on C:, but Win95 still did not boot. Then I booted into Linux, reran lilo with /dev/hda1 (the Win95 partition) as the thing to load, and got an error message (something about invalid partition specification). This did not bode well, I went into cfdisk to check, and indeed - the disk is 'empty' now, the MBR wiped clean.
Nothing to do then except to give it to a technician at our University (Koebenhavn), who suggested that he might be able to rescue at least the most important files. Thanks for your help to Oswald and Dave, Stefan -- PGP-ID: 4AF752D0