I'm not sure that those four-letter snippets are enough to hide the identity of the client.  Looks like a Stanley Hoover to me.  I'm curious what happened between October 2023 and March 2024.  Was the CP-2000 ignored, perhaps the same way the 1099-K was ignored?  Does the client have a clue as to who paid him $148,900 that year?  It should have been reported whether he received a 1099-K or not.  ("We have a tax on income, not on pieces of paper.")  Was it in fact reported?  Maybe on an 1120-S instead?  You don't generally see Schedules C with numbers that high.  

I found an Intuit EIN, and that's not it.  But they do have an office at that Woodland Hills  "high-rise campus setting" with a "26-story skyscraper" and "585,848 SQFT."  What are the chances that another tenant also has a name beginning with Intu?  Or that another building with a street number of 21650, somewhere in the world, matches that description?

In October I would have asked IRS for the information from the 1099-K, which has to include the full name and phone number.  It might not have been provided, and the easiest way to get it now may very well be to pay the $60 Tax Court petition fee.