Out of curiosity I downloaded the complaint that started the civil suit last June, with IRS suing for taxes it had not been able to collect.  The assessments were made in 2013, when two Tax Court cases were decided that related to years 1998-2007.  Those cases commenced in 2010 and 2012, so the statute for assessment must have been extended multiple times for the earlier years.  

IRS doesn't always (or even usually) record a lien because it can be detrimental to the taxpayers' credit rating and therefore their ability to remain in business.  So most of  the liens were not filed until 2019.  Oddly enough, the liens just for 2005-07 were filed in 2016.

This case was in the news recently because the IRS lawsuit had progressed to a point where some adverse actions were about to take place.  So, the Romanowskis filed a Chapter 11 bankruptcy on April 29, 2024.  Their home address is a 2710 square foot house in Lafayette, CA, worth about $2.3 million according to Zillow.  In other words, just your typical California home. 

Leave me a private message with your email address and I'll send you a pdf of the 18-page IRS complaint.