I hope it wasn't me that died 25 years ago and I forgot about it.  😂

Ugh, that situation sounds awful.  Although I don't know this for sure, I suspect that ProSeries is not set up for the 3 year rule of §1061.  If that is the case, you would need to manually calculate everything and override the software.  Ick.

Hopefully somebody that deals with Partnerships will come along and either verify that or tell you how to do it.  Another POSSIBLE option is that if I remember correctly, ProSeries users can use Lacerte on a Pay-Per-Return basis, and it is more likely that Lacerte would be able to handle it.  However, if you never have used Lacerte, that would involve a BIG learning curve, and that would probably be more work than just manually calculating things.