I have gone partway down this road myself. The idea was to mount a HD image with the loop option, which I have done with .iso CD images and NTFS partition images created with the dd command. I haven't had success yet, but this is what I have discovered so far...
1) Linux-based partition tools don't know Amiga-style Rigid Disk Blocks. When cfdisk, for example, looks for the partition table, that's where the RDB is and cfdisk concludes that the disk is unformatted. Win95 allegedly will, without prompting, attempt to repair the (nonexistent) partition table and trash the RDB, but there are tools to fix that.
2) The AFFS kernel modules, which permit reading Amiga disks, are not compiled by default. You have to compile your own kernel with "experimental file systems" or some such option turned on. The AFFS source code won't compile separately as a module; the makefile seems to rely on parameters passed to it when a whole kernel is compiled.
3) AFFS, according to its documentation, cannot mount Old File System as an image. The 488-byte blocks confuse the loop device, but FFS is ok.
So to do it this way, you would have to recompile a kernel with AFFS, mount the disk image with the loop option (if you don't need any OFS partitions) or copy the image to a left over hard drive (dd if=diskimage.img of=/dev/hdb , or /dev/hdd or whatever it is), and then mount it with the "-t affs" option. As for myself, I got as far as realizing I have to compile a kernel; I have compiled kernel *modules* but never a whole *kernel*.