I always got into the habit of writing down the details of partitions and associated information in a book for all my HDs. This really wasn't much use apart from being able to salvage the individual partitions later, the only sure way I suppose is to save the rdb information in a file. But who has the discipline to do these things as a natural course of action.
(Before you do the below you're going to have to unprep and reprep your HD)
In this situation what I would do is simply quick format the entire drive as one large partition, hopefully it was originally partitioned as per manufacturers specs otherwise that could introduce concerns about HD structure and set the correct filesystem on it too.
Then use DiskSalv to another HD with enough space for the process. It also has a guess Filesystem if you weren't sure about the filesystem and quick formatted it in something you guessed.
Too bad there wasn't a program that could find all the partitions then write all the information to the rdb.
Sorry this answer is somewhat vague and does rely on someone with ample knowledge of dos and workbench etc but like anything like this it takes far too much energy to write a thorough walkthrough, these days I normally say, this is too hands on to tackle
Perhaps someone can point you in a better direction
