I don't have a 13.5GB or 80GB HD (smallest is 200GB I think) but I'll see if I can set one up to the sizes required for an 80GB HD...
Reading & writing the RDB blocks on an HD is simple you just use one on the many PD tools like RDBTool from Aminet to read and write the HDs RDB blocks as a file, always handy in case your RDB gets corrupt for some reason and you need to rescue your HD...
EG:...
To save your HDs RDB to file for restoring a corrupted RDB (or even setting up a new HD of the same size)...
RDBTool DEVICE=scsi.device UNIT=0 File=RAM:200GB.rdb
To Write the file back to an HDs RDB blocks...
RDBTool DEVICE=scsi.device UNIT=0 WRITE File=RAM:200GB.rdb
Very easy and simple to do and save a lot of messing around partitioning and formatting HDs...
Leave it with me and I'll see what I can do...