ConvertIMP can change .imp metadata, but try it on a backup copy of your .imp to ensure it works properly for you.
If the .imp is not available to you, i.e. only on the EBW1150, then you would need to retrieve the .RES folder and convert it to a .imp using EBook-tools on CPAN. A bit more complicated, as it needs Perl to be installed, but known to work well.
Since reimp.exe (aka sbtest.exe) doesn't always work properly, it CAN be used to create a .imp but then you would need to "fix" it using ConvertIMP. A two-step process, but doesn't require Perl to be installed.
All these programs are described in our IMP software