Oracle 7.3.2 problem

I have returned to working with Oracle after an absence of more than a year and my skills are a bit rusty.

I have an Oracle 7.3.2 database running on SCO OpenServer 5.0.4. One of the disk drives, which contained only data files, failed and was replaced. The backup media was defective and could not be used. This, in itself is no major problem, as the amount of data is small and it can be easily reloaded from the original source.

The immediate problem is that Oracle will not start properly when datafiles are missing.

I have two ways of preceeding from this point, and I need help with both.

1. Convince Oracle to start properly, so that I can create a replacement for the missing data file and reload the missing data.
2. Re-install Oracle. This would require reloading all the data, but this only a minor inconvenience. The problem with this is that I can't find the (non-trivial) install instructions. The Oracle web site is no help. Support for Oracle 7.3.2 on SCO OpenServer 5.0.4 is long gone and all trace of it has vanished from the Oracle web site.