To second the "DD" suggestion: I'm guessing the RAW dump probably has several sectors worth of partition tables/driver-specific ID information that's going to mess up trying to simply mount the whole file. Can you determine where the HFS file system actually starts (and possibly ends) and trim the file down to that?
(Glancing at a reference on how HFS filesystems are structured I'd suggest looking at an HFS disk image and getting an idea what the boot blocks at LB positions 0 and 1 look like; those should be followed immediately by the "Master Directory Block". Hopefully those same parts of the filesystem are identical on the MacBottom. The only thing I worry about a *little bit* when you say this is a "RAW" dump is if the dump might include extraneous information between sectors. As I recall the formats for 800k Mac floppies and the HD-20 had a block of, what was it, 20 bytes? of "meta information" tacked on the end of each 512 byte sector. Do you see something like that in your raw file? I believe that's something left over from the Lisa and the Mac never used it, so I'm not sure if that information exists in "disk image" or emulator formats.)
(Glancing at a reference on how HFS filesystems are structured I'd suggest looking at an HFS disk image and getting an idea what the boot blocks at LB positions 0 and 1 look like; those should be followed immediately by the "Master Directory Block". Hopefully those same parts of the filesystem are identical on the MacBottom. The only thing I worry about a *little bit* when you say this is a "RAW" dump is if the dump might include extraneous information between sectors. As I recall the formats for 800k Mac floppies and the HD-20 had a block of, what was it, 20 bytes? of "meta information" tacked on the end of each 512 byte sector. Do you see something like that in your raw file? I believe that's something left over from the Lisa and the Mac never used it, so I'm not sure if that information exists in "disk image" or emulator formats.)